March/April 2025

Dear IOA members

 

As we enter the spring of 2025, I am delighted to inform you of the significant developments and ongoing projects at the IOA. Our progress and plans continue to shape our acoustics community. 

 

Chartered status progress
We have made good progress towards achieving chartered status for the IOA. The Grant of Arms, proudly shown at our 50th anniversary celebratory dinner at Vintners Hall, marks a big step in our journey. I thank Chris Turner for his leadership in drafting the petition for the award of chartered status to the King.

 

Noise Network Plus
We are pleased to welcome the launch if the Noise Network Plus, a £1.8M EPSRC-funded interdisciplinary network. The launch meeting is 18 March 2025 at the Royal Academy of Engineering. This project will tackle major noise pollution challenges for the next 10-15 years., complementing and continuing our efforts with UKAN+.

 

UKAN+ SIG integration plans
We are working to integrate UK Acoustics Network Plus (UKAN+) special interest groups (SIGs) into the IOA structure. A working party is developing a detailed integration plan, addressing membership requirements, resource allocation and alignment with IOA’s structure. A three-month, no cost extension for the UKAN+ grant has been secured, now ending on 30 June 2025. This gives us more time optimise the strengths of both organisations.

 

Noise impacts on wildlife
To support the UKAN+ SIGs, we are facilitating two EPSRC programme grants through a hybrid workshop on 4 June at the IOA HQ in Milton Keynes. The proposed grants, Quiet waters: aquatic ecosystem noise management, and Quiet earth: terrestrial ecosystem noise management, will address noise impacts on wildlife. Interested members should contact Helen Whitehead (SIGBio) at H.C.Whitehead1@salfird.ac.uk or Paul Lepper (SIGUA) at P.A.Lepper@lboro.ac.uk for more information.

 

Research initiatives
The IOA continues to support new research in acoustics and we are delighted to report progress in two key initiatives. The EPSRC Centre for Doctoral Training in Sustainable Sound Futures, led by Professor Trevor Cox, has welcomed its first group of PhD students. Many of these students are supported by our industry members. This project, involving the universities of Salford, Bristol, Sheffield and Southampton, aims to train 70 PhD students over the coming years.

Additionally, the Leverhulme Trust Aural Diversity Doctoral Research Hub, led by Professor Bill Davies, is currently recruiting PhD students for the 2025 group. This interdisciplinary project aligns with the IOA’s EDI objectives and focuses on understanding and addressing the wide range of hearing and listening differences among individuals.  

 

Standards revision
The IOA is actively involved in discussions about the revision of the British Standard BS 8233. A task-and-finish group was established in December 2024 to represent the interests of IOA members and help progress this important work. I thank Daniel Goodhand for his leadership of this group.

 

Communications and digital strategy
As previously reported we are enhancing our communication with members through  comprehensive digital transformation. You will see roll out of the new website this year. Our new website offers improved functionality and easier access to resources. As part of digital strategy, we will be welcoming a new Education Director to transform our educational delivery, by exploring innovative learning methods that blend online and in-person approaches. I encourage members to explore these new resources and provide feedback as we continue to improve your IOA experience.

 

Conclusion
As we move forward, I encourage all members to engage with these projects and contribute to the growth of our field. The IOA remains committed to advancing the science and practice of acoustics, and your participation is essential to our continued success.

 

Thank you for your ongoing support and dedication to the Institute of Acoustics

 

 

David Waddington, IOA President

 

 

 

 

 

 

 

 

Inspirational women in acoustics

 

 

Above: Photo credit: Andrew Beverley, CDM Stravitec UK

 

By Angela Lamacraft (Sustainable Acoustics Ltd), Vicky Wills (AtkinsRéalis), Reena Mahtani (Stantec UK) and Anne Budd (New Acoustics Ltd)

 

This incredible photograph of inspiring women was captured at the IOA’s 50th anniversary dinner, the details of which are covered on page 54 of this issue. We couldn’t let this opportunity pass by without comment, especially as International Women’s Day is 8 March, so let’s find out more about these fantastic acousticians:

 

 

1. Professor Dame Ann Dowling (OM, DBE, FRS, FREng), Deputy Vice-Chancellor and Emeritus Professor of Mechanical Engineering at the University of Cambridge. She is a Fellow of the Royal Society, Royal Academy of Engineering and is a Foreign Member of the US National Academy of Engineering, the Chinese Academy of Engineering and of the French Academy of Sciences. She is an Honorary Fellow of the Institution of Mechanical Engineers, the Institution of Engineering and Technology and the Institution of Engineering Designers and a Fellow of the Royal Aeronautical Society, the American Institute of Aeronautics and Astronautics and of the Institute of Acoustics. She has honorary degrees from 21 universities including Oxford, Imperial College London, Glasgow, the Technical University of Eindhoven, KTH Royal Institute of Technology Stockholm, Trinity College Dublin and McGill Canada.

 

A specialist in aeroacoustics, Dame Ann became the first female professor of Engineering at Cambridge in 1993 and went on to become the Head of the Department of Engineering at Cambridge University 2009-14 and President of the Royal Academy of Engineering 2014-19. She led the Cambridge MIT Silent Aircraft project, which published its radical new design concept, SAX-40, in 2006 with the aim of raising aircraft industry aspirations. She also chaired the agenda- setting and widely respected joint Royal Society/Royal Academy of Engineering report Nanoscience and nanotechnologies: opportunities and uncertainties published in 2004, which highlighted the need for responsible regulation and research around the use of materials at an extremely small scale – only a few millionths of a millimetre.

 

She was nominated in BBC Radio 4 Woman’s Hour power list 2013 as one of the 100 most influential women in the country. For her pioneering work in acoustical engineering, Dame Ann was awarded the IOA Engineering Medal in 2014 and she gave her medal lecture on the reduction of jet noise. In 2016 she was awarded the Institution of Mechanical Engineers’ James Watt International Gold Medal and in 2019 she received the Royal Society’ Royal Medal for her ‘leading research on the reduction of combustion, aerodynamic noise and the design of aircraft and her distinguished services to engineering’.

 

Finally, Dame Ann was the first female engineer to join the Order of Merit (OM), which only has 24 living members at any time, after being appointed by Her Majesty Queen Elizabeth II in 2016. She is only the tenth woman in over 100 years to join the OM, following in the footsteps of some uniquely accomplished women from politics, science and the arts.

 

2. Jenny King (AMIOA), Acoustic Consultant at AECOM, member and early careers representative of the IOA STEM Committee, is a regular attendee at the London Branch meetings and was awarded Highly Commended for the John Connell Rising Star Award 2024. Though relatively new to the field of acoustics, Jenny has already made significant contributions to our industry through her passion for STEM as well as acoustics as a whole and this has quickly established her as a prominent figure in the community.

 

3. Eleanor Girdziusz (MIOA), Senior Associate and Building Acoustics Lead at Stantec UK in London, an IOA Diploma Examiner in Building Acoustics and part of the team that put together the acoustic work experience on Springpod. She has trained as a secondary school teacher and brings her passion for training and education to the work she does.

 

4. Fiona Rogerson (MIOA), Senior Acoustic Consultant at Arup, Honorary Secretary of the IOA, serving on the Executive Committee and IOA Council, and a long-standing member, and past Chair of IOA Midlands Branch. Fiona has a strong interest in people and their development, as well as a passion for equity, and is currently mentoring champion for the Arup Acoustics team.

 

5. Vicky Wills (FIOA), Associate Acoustic Consultant at AtkinsRéalis, member of IOA London Branch, IOA STEM Committee and ANC Future Acousticians, winner of the IOA ‘Promoting Acoustics to the Public Award’ and listed as one of the Top 50 Most Influential Women in Engineering in 2016. Vicky has worked at AtkinsRéalis (was Atkins) since 2001, mainly focusing on the assessment of environmental noise from large road schemes. She has brought acoustics to the attention of hundreds of children through her tireless work promoting STEM, and particularly acoustics, within schools and at careers fairs.

 

6. Angela Lamacraft (IEng FIOA), Senior Acoustic Consultant at Sustainable Acoustics Ltd, current Trustee and Council member of the IOA, founder and former Chair of the IOA Equity, Diversity and Inclusion Working Group, Chair of the IOA School Competition Committee, former Chair of the IOA Young Members Group and various other IOA and ANC roles. Angela is an acoustic consultant at Sustainable Acoustics Ltd, working on environmental, industrial and building acoustics projects. She works tirelessly to promote the benefits of equity, diversity and inclusion within the IOA and members’ organisations. She was awarded the IOA Award for Promoting Acoustics to the Public in 2024.

 

7. Sam Riley (MIOA), Acoustic Consultant at dB Consultation Ltd. Now working full time in environmental acoustics, Sam previously worked in Environmental Protection for 32 years. She obtained the first Public Space Protection Order after the legislation was released in 2014 to stop car meets in a car park and associated noise from local roads being used as a race circuit.

 

8. Elle Hewett (MIOA, MAAS), Associate Consultant at Stantec UK in Bristol. Elle has worked most of her career in Sydney, Australia and is enthusiastic about good acoustic design. She is part of the ANC’s marketing committee and one of her projects in Australia won the 2023 ANC Sustainability award.

 

9. Daniela Filipe (MIOA), Head of Acoustics at Experience Studios in London. She is a member of the IOA Building Acoustics Group and regularly presents for the IOA on events such as The Art of Being a Consultant. In 2020 one of her projects won the ANC Environmental award.

 

10. Jo Webb (CEng HonFIOA), Vice President International of the IOA following a term as President of the Institute 2016-2018, and member of the Parliamentary Liaison Group and North West Branch Committee. Jo has also been part of the IOA Membership Committee and the Noise and Vibration Engineering Group. She was educated at the University of Salford graduating in 1987 from the electroacoustics course and later gaining a masters in acoustics. She is now back at Salford following a 35 year career in consultancy. She was a Technical Director of Wood Group, an Associate at Arup Acoustics where she worked for 18 years, and had jobs at various other consultancies as well as in a local authority, after starting her career with Building Design Partnership. Jo is undertaking research for a PhD sponsored by the Royal Horticultural Society in the potential of natural noise control as part of a wider study of the ecosystem services of hedges. As well as her research work Jo now spends time encouraging and supporting others to build careers in acoustics through the UK Acoustics Network and the university.

 

11. June McClung (MIOA), Noise Manager at Edinburgh Airport. She started out as an analytical chemist at the Scottish Environmental Protection Agency, moving into Environmental Health in 2005 and spent 12 years in local authority environmental health/ pollution control in Scotland and Wales. For the past eight years June has been managing noise at Edinburgh Airport, involved in airspace change – modernising Edinburgh Airport’s flightpaths to minimise the number of people overflown, managing the airport’s five-year noise action plan process and public consultation, community noise board and noise insulation scheme. June is also a member of the IOA Publications Committee and is active in the IOA Scottish Branch.

 

12. Anne Budd (MIOA MASA), owner and Director at New Acoustics Ltd since 2005 and Chair of IOA Scottish Branch. She has worked internationally as a product manager for acoustic instrumentation and standardisation, conducted research into school acoustics, speech intelligibility of young children and teachers’ voices, and is currently an acoustic consultant. Anne was the first woman to be elected in a contested vote to the board of the ANC and is a member of the ANC Future Acousticians Group and the ANC Sports and Leisure Noise Working Group.

 

Anne has previously been Secretary of IOA London Branch, member of and Early Careers Representative on IOA Council, Secretary of the Building Acoustics Group, member of the IOA Women and Families Working Group, member of IOA Scottish Branch committee, has led consultations and drafted responses on behalf of the IOA and has taken an active role in the organisation of IOA conferences and meetings. She is currently a member of the IOA Parliamentary Liaison Group representing Scotland and continues to volunteer in STEM-related activities on behalf of the IOA promoting acoustics wherever she can.

 

13. Josie Nixon (MIOA), Principal Acoustic Consultant at HA-Acoustics, former Chair of the IOA Early Careers Group, Secretary of the IOA Eastern Branch and member of the IOA Bursary panel. Josie’s enthusiasm for supporting people at the beginning of their career in acoustics has undoubtedly helped many budding acousticians. She mainly works in environmental acoustics and her proudest achievement is the diversity of her past projects. Whether undertaking a foundry noise at work survey, monitoring music festivals, producing noise impact assessments to support planning applications or UKAS sound insulation testing.

 

14. Bridget Shield (MBE FASA HonFIOA), Emerita Professor of Acoustics at London South Bank University and the first woman President of the IOA (2012-2014). Bridget was one of just a few women members when she joined the IOA. After serving on several IOA committees she became its first female Council member, first female Fellow, and first female Honorary Fellow. In 2021 she was awarded an MBE in the Queen’s Birthday Honours for her ‘services to Acoustic Science and to inclusion in Science and Engineering’. Professor Shield retired from London South Bank University after 30 years during which time she co-founded the national Women in Engineering Centre at the University and was course director of the MSc in Environmental and Architectural Acoustics.

 

Bridget’s research interests included railway noise, concert hall acoustics, hospital noise and the social and economic costs of hearing loss in Europe. Her major research activity for 20 years, in collaboration with Professor Julie Dockrell of the Institute of Education, focused on the effects of noise and poor acoustics on children and teachers in primary and secondary schools. In 2003 she was appointed by the Department for Education and Employment as editor of Building Bulletin 93 (BB93), which contains the acoustic performance specifications for schools. Bridget has taken an active role in increasing public understanding of science and has prided herself on being a role model for women, promoting women, diversity and inclusivity in acoustics throughout her career. Professor Shield’s work has attracted major national and international accolades; she was elected as an Honorary Fellow of the IOA and awarded the Institute’s RWB Stephens Medal. She also received the UK Noise Abatement Society’s Lifetime Achievement Award and was awarded a Fellowship from the Acoustical Society of America. 

 

15. Sarah Huskie (MIOA), Managing Director of CDM Stravitec UK. She is a member of the IOA EDI working group and one of the judges of the ANC awards. She was also the Secretary of the Middle East Branch of the IOA and has led teams in the UK, the Middle East and Asia Pacific, working on projects such as the Marina Bay Sands in Singapore. She has a personal interest in health and fitness, which fits amazingly well in her daily work.

 

16. Abigail Bristow (FIOA), Professor of Civil and Environmental Engineering at the University of Surrey, Fellow of the Royal Society of the Arts and the Chartered Institution of Highways and Transportation, and currently a co-investigator for UKAN+. Abigail has extensive experience in research in the areas of transport management and policy, most notably appraisal of the environmental effects of transport with particular focus on noise and climate change.

 

17. Sue Bird (MBE CEng FIOA) has been a member of the IOA since its foundation. She has been the President of the Women’s Engineering Society (WES) twice and helped set up the International Network of Women Engineers and Scientists (INWES) where she was President for three years. She was granted an MBE for ‘Services to engineering and to women into engineering both in the UK and abroad’ and awarded the Elizabeth Hardwich medal of WES. In 1992 she was part of the government working group which produced the report ‘The Rising Tide ‘ concerning women in STEM.

Sue served as Chair and later President of the Association of Noise Consultants and as the senior examiner for the registration scheme for 10 years. She is also named as an Honorary Member of the ANC. She initiated the CPD committee at the IOA, and is still working on this, helping to assess members’ records. She has worked in the aircraft industry, in local government, and for 22 years as a partner in Bird Acoustics. Even though she is retired, she is still a very active part of the acoustics industry, volunteering her time as Chair of Judges of the ANC awards and on the IOA CPD committee.

 

18. Reena Mahtani (FIOA FWES IEng), Principal Consultant at Stantec UK. She is a Trustee and Council member of the IOA, the Chair of the Bursary Fund, the Secretary of the Southern Branch Committee and a member of the Sustainability and Soundscapes working groups of the ANC. Reena has worked in projects both in the UK and Singapore and has an interest on making the acoustics industry more inclusive and welcoming.

 

Out of shot: Louise Beamish (MIOA), Director of Acoustics at WSP and board member and current Chair of the ANC. Louise has led several industry groups and committees, such as the IOA London Branch, the ANC Marketing Committee, was Chair of the Trailblazer Group for the Environmental Practitioner Degree Apprenticeship and she established the IOA Early Careers Group. She has been able to bring her passion for championing women in STEM careers, as well as her enthusiasm for industry-wide collaboration and innovation, and continues to have a positive influence on the acoustics industry through her role at the ANC.

 

What an incredible bunch, between them committing huge amounts of time and effort into helping the acoustics profession, both technically and in terms of governance and leadership.

There are, of course, many awe-inspiring women in acoustics who were not at the dinner, and there are many other groups of members that could be written about. We would love to hear more about our diverse membership so please submit an article to the IOA or a post for the EDI blog (diversity@ioa.org.uk) if you would like to raise awareness of other members.

 

 

 

 

 

 

 

 

 

Lottie Doll Tour 2024

 

The IOA celebrated Tomorrow’s Engineers Week for the first time in 2023 by taking part in the Lottie Tour. The tour is a Women’s Engineering Society (WES) initiative, to inspire young minds by showcasing the diverse world of engineering, or in our case, acoustics.

 

By Vicky Wills, IOA STEM Committee

 

In 2023 we sent Lottie to several of our members and they took pictures and made videos of the doll doing work experience in their workplace. We collected the pictures from Lottie’s adventures, and through a series of compilation videos we showed that she was learning about the wide variety of careers in acoustics. The Lottie Tour continued in 2024, with even more companies participating and sharing their experiences. Numerous organisations posted updates on social media, showcasing what Lottie got up to at their workplace and out on site or at events. The companies that posted included AECOM, Anderson Acoustics, AtkinsRéalis, CDM Stravitec, Christie & Grey, Create Consulting Engineers, HA Acoustics, Hann Tucker, Hoare Lea, L-Acoustics, Napier University, New Acoustics, RBA Acoustics, Sandy Brown, Stantec, Sustainable Acoustics, Vanguardia, UKHSA and WSP.

 

In 2024, the IOA took the initiative further by creating four engaging stop-motion animations featuring Lottie. These animations, designed to spark interest in careers in acoustics, creatively illustrate aspects of the field, from environmental noise control to architectural acoustics.

 

1. Types of Noise: This video showed the dolls being affected by noise from transportation, workplaces and nightclubs. It received 10 reposts and more than 550 views on LinkedIn. It had five reposts and more than 700 views on X. Additionally, Instagram had 145 views, TikTok 229 views and Facebook 102 views. See the video here: https://tinyurl.com/Lottietypesofnoise

 

2. Tackling Harmful Noise: This video featured the dolls discussing noise and its health effects. It garnered over 400 views and four reposts on LinkedIn. It had over 400 views on X and four reposts. Additionally, Instagram had 69 views, TikTok 219 views and Facebook 56 views. See the video here: https://tinyurl.com/Lottieharmfulnoise

 

3. Standards in Controlling Noise: Focusing on different types of noise and what acousticians can do to help mitigate unwanted noise, this video was viewed almost 150 times and reposted once on LinkedIn, with almost 400 views and three reposts on X. Additionally, Instagram had 76 views, TikTok 216 views and Facebook 59 views. See the video here: https://tinyurl.com/Lottiecontrollingnoise

 

4. Underwater Sound: This video highlighted how sound acts differently in water and its impact on wildlife, as well as applications of underwater acoustics. It was viewed more than 250 times and reposted five times on LinkedIn. It was viewed more than 500 times on X and reposted three times. Additionally, Instagram had 132 views, TikTok 223 views and Facebook 54 views. See the video here: https://tinyurl.com/Lottieunderwatersound

 

All four videos linked back to careers in acoustics, emphasising the exciting opportunities in this field. The videos will be reused for the 2025 campaign and will become part of the content for the new public section of the IOA website, which is likely to be launched in 2026. We are incredibly proud of how the industry has come together to promote this initiative and, along with the other work that the IOA is doing on STEM, we hope we are paving the way for the next generation of acousticians.

 

Tomorrow’s Engineers Week is a national campaign run by Engineering UK to increase the diversity and number of young people entering engineering careers. (https://www.tomorrowsengineers.org.uk/)

 

Below: A still from the Types of Noise video, with two Lottie dolls covering their ears after a night of clubbing

 

 

 

 

 

 

 

 

 

 

New guidance launched to support compliance with Approved Document O

 

The Association of Noise Consultants and the IOA have partnered to deliver a comprehensive guide to raise wider awareness of acoustics in relation to Approved Document O.

 

The 38-page Approved Document O Noise Guide lays out the requirements set down in the Building Regulations, focusing on overheating mitigation in new residential buildings. A working group of industry experts from the ANC and IOA has worked on the advice, which sets out a method to demonstrate compliance to the Building Control Body of the noise constraints in Approved Document O. It supersedes the Guide to Demonstrating Compliance with the Noise Requirements of Approved Document O, which was a draft for consultation.

In the latest document, the statutory guidance relevant to the industry in Approved Document O is explained and the authors have focused on overheating mitigation using methods such as opening windows, ventilation louvres in external walls, mechanical ventilation and mechanical cooling systems. Louise Beamish, Chair of the ANC, said: “This guide sets out a method to demonstrate compliance to the Building Control Body of the noise constraints in Approved Document O. It aims to provide clarity for practitioners and regulators so that assessments can be carried out consistently, and the outcome is repeatable and reliable.”

 

Chair of the Working Group, James Healey added: “Meeting the requirements of Approved Document O has been a challenge for developers, particularly from a design coordination perspective and due to varied interpretations of the approach, which affect the route to compliance. This latest guide offers an extensive evaluation of all the methods available to developers of residential properties, with contributions from the principal authors of the Acoustics, Ventilation and Overheating Guide. It provides guidance for practitioners to appropriately implement the requirements of Approved Document O, assists the industry in the understanding of what is published in the regulation and uses award-winning research to provide an approach that uses one language form for both acousticians and thermal modellers to increase coordination.

 

Whilst the requirements of Approved Document O are succinct, there is some ambiguity regarding important details. Some of these have been addressed in this new guide, whic h provides interpretation and clarification on content within a published regulation.”

 

The guide is available for free download at https://www.association-of-noise-consultants.co.uk/approved-document-o-noise-guide/ 

 

 

 

 

 

 

 

 

 

 

Acoustic biodiversity monitoring with hopping robots

 

Understanding how animals are distributed cross our planet, how they move and how they behave is essential if we are to protect biodiversity in the face of increasing human pressures. However, in practice, collecting insightful monitoring data at meaningful scales and resolutions remains extremely challenging.

 

By Sarab S. Sethi, lecturer in ecosystem sensing, Department of Life Sciences / I-X, Imperial College London

 

Traditional approaches to collecting biodiversity data rely on manual surveys conducted by trained experts. For example, in a bird point count an ornithologist will stand at a site of interest and record every single bird that they see or hear over a fixed period. Whilst data quality can be exceptional (e.g. identifying sex, age, or breeding stage is possible), the slow speed and high cost of surveys very quickly becomes a major barrier to scalability.

 

Acoustic monitoring has recently seen a surge in popularity as a scalable alternative to surveying animals in the wild. Inexpensive audio recorders are deployed to capture natural soundscapes from sites of interest over weeks and months. Audio is then analysed with machine learning algorithms to identify species from their vocalisations (e.g. birds by their calls and songs) or other unique acoustic cues (e.g. mosquitos by their buzzing frequencies). Still, whilst recorders themselves can be cheap, deploying, maintaining and retrieving them can become prohibitively expensive and time-consuming when species need to be monitored on landscape scales or over extended time periods.

 

Below: Drones carrying acoustic sensors might be able to transform the scale at which we can monitor biodiversity

 

 

Drones on the hop
In a pilot project funded by the UK Acoustics Network (UKAN+), Dr Peggy Bevan led explorations into whether autonomous robots (e.g. drones) carrying acoustic sensors might be able to transform the scale at which we can monitor biodiversity.

 

Using a vast dataset of audio recorded from ~300 sites across tropical rainforests and agricultural lands on the Osa Peninsula, Costa Rica, we simulated autonomous drones hopping between sampling sites recording an hour of audio at a time. Whilst the original dataset had complete temporal data coverage at each site, our simulated drones could only record short snippets of audio while they briefly landed at a sampling site.

 

We found that even when simulating very lightweight sampling networks (e.g. one drone per five-10 sites), we could reconstruct previously published patterns in bird biodiversity and spider monkey occupancy across the region. We also found that adaptive sampling – using real-time data to inform which site the drone visited next – improved the reliability of our downstream biodiversity data.

 

Reducing costs and increasing scalability
In other research from our group at Imperial (the Ecosystem Sensing Group) and collaborators across Europe, we are developing technologies that will make autonomous biodiversity sensing systems of this type a reality. For example, Mili Ostojic is developing an autonomous drone that can navigate through complex natural environments and Dr Clementine Boutry and Javad Bathaei at TU Delft are developing fully biodegradable sensors that could be deployed from robotic platforms of this kind.

 

More engineering research and development work certainly remains before robotic sampling systems reach full maturity and are available at reasonable price points. Nevertheless, our research has paved a clear pathway for autonomous robotic platforms to deliver reliable and impactful data whilst reducing costs and increasing scalability of biodiversity surveys in the future.

 

 

Above: Collaborators throughout Europe are developing technologies that will make autonomous biodiversity sensing systems a reality

 

 

 

 

 

 

 

 

 

 

Tomorrow belongs to those who can hear it coming

 

Ruth Moslin recently achieved a first class degree in audio engineering from the University of the Highlands and Islands in Scotland. For her research she wrote a paper on soundscapes and how they affect our creative, mental and ecological worlds. This is a shortened version (complete with sound effects).

 

By Ruth Moslin

 

'Tomorrow belongs to those who can hear it coming’ – a phrase used by David Bowie to promote his 1977 album Heroes. Although Bowie was most likely referring to the fluctuating political and fashionable trends prevalent at the time, the phrase has since been used in discussions relating to the earth’s sonic landscape and it’s ever-changing biophonic, geophonic and anthrophonic soundscapes.

 

The first known audio recording of a biophonic non-human source was captured on the earliest available commercial recording device, the wax phonograph cylinder. Frankfurt born, Ludwig Koch, caught the song of a captive shama bird in 1889 and while this is an impressive achievement alone, Koch was only eight years-old at the time. Since then, birdsong has been used in extraordinary ways as both artwork and in healing practices. (Listen here https://www.bbc.co.uk/ sounds/play/b00jn4m2)

 

Birdsong
Combining human sound and the environment in 2015, Robin Perkins released the album A guide to the birdsong of South America which contains calls from endangered birds across the continent to raise money for non-profit organisations. While birdcalls vary through species, they are known to be beneficial to mental health, but setting aside the pig-like grunt from the Atlantic puffin, why do humans find birdsong so calming?

 

Birdsong falls within the frequencies known as the ‘sweet spot range for human hearing’ (1,000Hz-8,000Hz). Electroencephalography (EEG) measures brain waves and is broken up in to gamma, beta, alpha, delta and theta frequency bands, which fall within our sweet spot range. Theta waves have been shown to be strongly present during internal focus activities, such as meditation and relaxation – possibly providing the insight into why birdsong is used so widely for therapeutic uses.

 

 

Above: Setting aside the ‘pig-like grunt’ of the Atlantic puffin, humans find birdsong calming

 

These days recorded birdsong is not just found in relaxing Spotify playlists or BBC’s Springwatch. Alder Hey Children’s Hospital in Liverpool has played birdsong in its corridors since 2010, the recordings, which were captured at a nearby park, are seen to uplift spirits and boost relaxation. A similar concept can be found in Amsterdam’s Schiphol Airport where birdsong recordings are used in lounges to promote relaxation before flights. (Listen to birdsong therapy here https://www.birdnote.org/podcasts/ birdnote-daily/birdsong-therapy)

 

However, unlike Ludwig Koch’s shama recording, the most mesmerising bird song will not be recorded from those in captivity – so what is the best way to capture these sounds? Paying homage to the Heinrich Hertz 1888 parabolic antenna, the parabolic shield has it’s uses for birdcall recording, its concave design, which gathers sound into a focal point can be paired with an omni-directional microphone that provides the ability to capture the very best of dawn choruses. In his book, The Singing Life of Birds , ornithologist Donald Kroodsma compares the parabolic shield and shotgun microphone for their qualities in bird call recording. Kroodsma suggests that the parabolic microphone is far more capable of capturing soft and distant sounds, however, it doesn’t capture the birds as heard by the human ear, such as that of a quasi-binaural microphone set up.

 

Although the parabolic microphone covers a much larger area than that of a shotgun, the shotgun manages to capture more echo and uncertain sounds – making birdsong sound a little ‘smudgy’. Despite the disadvantages they pose on recording birdsong, shotgun mic’s are better at capturing low frequency sounds and are used for recording outdoor sounds such as psithurism (the sound of wind blowing through trees), which brings us neatly to the next sonic attribute – geophony.

 

Geophony
Geophonic sounds describe any sound created by nature, reminding us how powerful the earth can be and how it is continuously on the move. In 2020, the sounds of the melting Kongsvegan glacier in Norwegian archipelago, Svalbard, were recorded by researcher, Ugo Nanni¹ , using a seismometer, where the frequencies recorded fell between 1-100hz. These infrasonic recordings were processed to be audible and contained the constant sound of cracking ice around the melting glacier, despite its visual stillness.

 

According a 2021 study by Noise & Health² , low frequency sounds can be dangerous to humans. The study concluded that within one hour of exposure to infrasonic sounds of more than 100 dB, there is interference with the human cardiac muscle, increased nausea and sleep disorders in participants. London’s Gatwick airport is home to the largest soundscape installation that incorporates geophonic sounds – A Living River . Using over 60,000 meters of speaker cable, the installation contains a series of hydrophone recordings captured along China’s Yangtze river that plays to those walking along Skybridge, the 180m-long airport corridor, the installation is supported by WWF who also promote alternative methods of travel over aeroplanes to cut aviation pollution and aircraft noise. Listen here: https://www.dandad.org/ awards/professional/2016/ branding/25407/living-river/

 

Below: Songs of the Humpback Whale (1970) by Roger Payne showed that whales could sing and communicate in rhythm

 

 

Under water
In 1490, Leonardo Di Vinci was credited for the first noted evidence that sound travels under water. One of the most influential uses of a piezoelectric hydrophone dates back as far as World War I when Canadian inventor, Reginald Fessenden, used a hydrophone in 1914 to detect an iceberg in the hope of avoiding a repeat of the Titanic disaster two years prior. Further developments using hydrophones include arrays where several are placed across the ocean floor to record data. This method has uses for recording the position of marine life and has been modernised by the US navy who tow a hydrophone line array behind ships to locate enemy submarine positions.

 

Forming a creative use, the muti-platinum album, Songs of the Humpback Whale (1970) by Roger Payne showed that whales could sing and communicate in rhythm. Payne’s album is the most successful nature recording of all time and kick-started the Save the Whales movement, which eventually led to the banning of commercial whale hunting in 1986. More recently in 2023, James Crutchfield developed a hydroambiphone – a 3D underwater audio recorder which he used to record humpback whales in Alaska.

 

Continuous research into anthropocene soundscapes on marine life has been studied due to the qualities of hydrophones recording. The EU set limits on underwater noise pollution, so since March 2024, no more than 20% of a marine area can be exposed to continuous underwater noise during a given year and no more than 20% of a marine habitat can be exposed to impulsive noise over one day – an incredible step forward given the EU’s continuous and expanding shipping traffic.

 

Archeoacoustics
The combination of archaeology and acoustics (archaeoacoustics) uncovered large granite rocks known as gong rocks in the Serengeti National Park in Tanzania, believed to date back as far as the middle-ages. Similarly, ‘The Ringing Stone’ in Tiree, Scotland is thought to have arrived from the Isle of Rùm during the last ice age. These carved and decorated rocks are lithophones and when hit with a stone produce sounds believed to have been a form of communication for gathering people, warning signals and rituals. Listen to the gong rocks here https://tinyurl.com/gongrock

 

Sound anthropologist, Iégor Reznikoff, studied sound within painted caves and rocks and found that areas with a higher resonation rate generally contained more paintings dating back to the palaeolithic period, providing evidence that they were used as very early amphitheatres. Today, a more contemporary use of these resonating caves is found inside the Luray Caverns in Virginia, USA. An organ is fixed in place to vibrate the caves’ stalactites and is now known as the largest musical instrument in the world. Listen here: https://www.sonicwonders.org/ great-stalacpipe-organ-usa/

 

Urban landscapes
The best example of an anthrophonic soundscape is, of course, a city. In 1928, The Daily Mail recorded the urban soundscapes of London with the specific aim to highlight traffic noise. Five of those recordings were published on gramophone, played on BBC radio and almost instantly, officials in London took immediate action to minimise traffic noise by placing limitations on the use of car horns. Fast forward to 2020, these recordings were made available to visitors at the Museum of London³ alongside updated recordings from the same locations to allow listeners compare (recognising that because of the pandemic the streets of London were significantly quieter at that time).

 

Lead by R Murray Schafer, the World Soundscape Project aimed to bring together research on the scientific, sociological and aesthetic aspects of the acoustic environment. The Vancouver Soundscape was one of the group’s first releases in 1973 where listeners could be re-cast to late 1970’s Vancouver with the recordings capturing the reality of a working industrial city. Two of the group’s members, Barry Truax and Hildegard Westerkamp were involved in the 1996 re-issue of the project aiming to highlight the changes in Vancouver’s soundscape over the years and provided an audible difference from the stereo Nagra analogue recorder used by the group for the first recordings.

 

Infrasonic sounds
Of course, another way to identify sound is to visually inspect the frequencies in audio signals from spectrogram software. By using spectrograms, bioacousticians have been able to research a range of mammals’ infrasonic sounds, particularly those of elephants. Researchers at Cornell University’s Elephant Listening Project estimate that because of elephants’ infrasonic range humans can only hear around 40% of the animals’ sounds. But by using acoustic arrays to record elephant calling, researchers have discovered that elephants have a four-octave frequency range, reaching between 27Hz and 470Hz – pretty handy when you are trying to reach your friend over six miles away. Creatively, spectrograms are also used as an artform. In late 90s a trend of artists ‘hiding’ spectrogram artwork in their music began, one of these was Cornish artist, Aphex Twin, whose track Equation was hiding his own face at the end of the track using a spectrum of frequencies, of course it could be argued that animal calls are a lot more pleasing to listen to! Listen here: https://www.youtube.com/watch?v=M9xMuPWAZW8

 

Biophilia
There is now evidence that humans find that biophonic and geophonic sounds more relaxing than anthropogenic sound. Naturalist Dr Edward Wilson, used the term ‘biophilia’ to describe the tendency that humanity as a whole has to be drawn towards nature. Supporting his theory is the trend of shinrin-yoku (forest bathing) – a Japanese practice of surrounding oneself in nature. To test this, researchers for BBC series, Forest 404, immersed participants in sounds of rainforests, woodlands and coastal areas to record the psychological impact it had on them. Results recorded from the study in those who practiced it included lowered blood pressure, lower heart rate and a decrease in the stress hormone, cortisol – assisting the stress recovery and the attention restoration theories. In 2017, the University of Sussex exposed 17 participants to a series of natural and artificial sounds. During listening, functional magnetic resonance imaging (fMRI) scans were produced, allowing the researchers to have a visualised demonstration on the effects of natural sounds. The results showed improved internal focus, lowered blood pressure, decrease in the body’s sympathetic response (flight or flight mode) and an increase in the body’s parasympathetic response (relaxation).

 

Given that every soundscape has its own unique elements which create its sonic characteristics, it would be challenging to provide only one explanation as to why they provide us with the affects they do. Without a doubt one aspect is for certain – as urbanisation grows rapidly and our natural surroundings change, this could well be an opportune time to capture our sonic landscape and map the continuous changes in our rapidly changing world.

 

References
1. https://edm.com/lifestyle/ambient-glacier-sounds-climate-change-effects
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8411947/#:~:text=Exposure%20to%20high%20levels%20of,as%20one%20hour%20after%20exposure
3. https://www.londonmuseum.org.uk/blog/recording-londons-soundscapes-past-present/

 

 

 

 

 

 

 

 

 

 

 

Reproduced Sound 2024

 

The Reproduced Sound 2024 conference and exhibition was held last November in Bristol. The conference represents the cutting edge of modern audio and acoustics in an informal environment that allows consultants, manufacturers, contractors, end users, academics and students to mingle and share insights and information.

 

By Adam Hill

 

Organisation of the conference was led by IOA Electroacoustics Group (EAG) Chair, Ludo Ausiello (University of Portsmouth, UK), supported by the 14 committee members and the IOA’s Linda Canty. Complete audio-visual support was coordinated by EAG committee members, Adam Hockley and Andrew Horsburgh, along with student assistant, Jamie, from dBs Institute of Sound & Digital Technologies, Bristol. d&b audiotechnik have generously provided technical support for Reproduced Sound for many years, to the great benefit of the conference. The conference was held at the Bristol Hotel where there were around 60 delegates, representing a healthy balance between industry and academia.

 

Pre-conference activities
Reproduced Sound (RS) often includes a special event the evening before it officially opens, consisting of a more informal talk and demonstration from members of industry or academia. The RS organising committee sourced several examples of classic analogue synthesisers and modern digital/hybrid clones for this year’s Tuesday evening workshop. The session saw attendees discussing multiple synthesiser technologies from pure analogue, hybrid, to purely digital, and debated about timbre, soundwaves and perception while attempting measurements on various devices.

 

 

Above: EAG Chair, Ludo Ausiello

 

Conference day one
The first formal day of the 40th RS conference was launched by Ludo Ausiello, who welcomed delegates and thanked the technical team for their hard work preparing for the conference in order to deliver excellent audio and video support, something RS delegates have benefitted from for many years.

 

Awards
Peter Barnett Memorial Award – Keith Holland
The 2024 Peter Barnett Memorial Award recipient was long-time RS attendee and former IOA EAG Committee Chair, Keith Holland. IOA Past President, Alistair Sommerville, was on hand to present the award to Keith. Glenn Leembruggen read out the award citation citing Keith’s inspirational work over many years covering a wide range of research topics, which has had a huge impact on electroacoustics, specifically on loudspeaker and studio design. 

 

Below: Keith Holland receiving the Peter Barnett Memorial Award 2024 from IOA Past President, Alistair Sommerville

 

 

Keith’s lecture, Acoustics: inside out and back to front , provided a fascinating overview of Keith’s life in audio and acoustics, starting back in the 1960s when he built his first Hi-Fi. He progressed to working in live sound while studying at ISVR in the 1980s, where he began a long-term collaboration with Philip Newell in 1987, when Philip sponsored Keith’s PhD.

 

Keith talked about how he spent a good deal of time during his career looking at acoustics problems including:
* acoustic reciprocity;
* acoustic inversion methods; and
* nonlinear horn modelling.
With this laid out, Keith went through a series of interesting and challenging projects he worked on, from noise control to jet engine noise analysis with Rolls Royce.

 

Keith’s excellent teaching ability was on show, as he was able to explain what could be seen as complicated ideas in an easy to grasp manner, especially his treatment of Green’s function at various points in the presentation by relating the mathematics directly to the real-world. The talk was very well received by the delegates and there were numerous questions, largely focusing on analytical modelling and its limitations.

 

SESSION ONE – Spatial audio 1 (Chair, Keith Holland)
Beyond the frame – textural realisation in cinema sound
The first paper of the conference was delivered by Sharon Coleclough from Staffordshire University. Sharon spoke of the importance of a nuanced and active sound design for film, ensuring audio is synced with all the other senses. She highlighted the usefulness of ‘juicy audio’ to provide positive feedback. This approach to sound design has already been implemented in her teaching, where her students are encouraged to play and experiment with their work.

 

And then it turned outside-in: new insights into spatial game audio
The next paper on spatial audio was delivered by Sharon’s colleague, Mat Dalgleish from the Staffordshire University Games Institute. Mat spoke on a gradual move away from realism in game audio (‘inside-out’), which was supported by a brief history of sound for games. Now there is perhaps a need to move back towards realism (‘outside-in’) to provide a better sense of closeness, which is integral to effective gameplay.

 

Demystifying crosstalk cancellation
The final paper of the session was delivered by Jacob Hollebon from Audioscenic. Jacob began his talk with a general explanation of how crosstalk cancellation works, highlighting the issues with half wavelength propagation path differences between sources. In his work, the approach isn’t to tackle this problem head on, but to add more loudspeakers to decrease spacing between transducers. This allows for a lower direct to reverberant ratio, leading to shorter impulse responses for use within the crosstalk cancellation system. Results looked to be promising, where headtracking is used to maintain accurate localisation.

 

SESSION TWO – Transducers (Chair, Ludo Ausiello)
Looking at the ear as a compressed sensing system
The second paper session of the conference, on transducers, was kicked off by long-time RS contributor, Jamie Angus-Whiteoak. This year, Jamie talked about the ear as an optimised compressed sensing system, which takes advantage of signal sparsity. While audio signals are dense in the time domain, they are sparse in the frequency domain, which is effectively how our ears process incoming signals. In terms of sampling, this is governed by when our nerve fibres fire, which turns out have random spacing in time. This leads to the conclusion that the ear may be a front end for a compressive sensing system, taking advantage of sparse sampling, which should be explored with further research.

 

Iterative metric-based waveguide optimisation
Lewis Macdonald from Celestion delivered the second paper of the session, looking into a method for waveguide optimisation, specifically the new ‘lensguide’ technology. This is achieved through corrugations and thickness variations to control wave propagation through a device. The optimisation procedure uses a set of performance metrics within an iterative procedure. These metrics are stretch (corrugations) and thickness (seen area). While this provides extended high frequency control, it does result in higher manufacturing costs. Lewis concluded his talk with several example applications of this work, which prompted many enthusiastic questions and comments from the delegates.

 

Below: Jamie Angus-Whiteoak delivering her talk

 

 

Tuning and performance evaluation for surface mounted audio haptic transducer systems
Stephen Oxnard, current Chair of the Audio Engineering Society UK Section, delivered the third paper of the session, which was a continuation of his research into surface mounted haptic systems. The focus of the work is on transparency of the audio tactile response. Essentially, the question is what makes a good system and how can this be quantified. Stephen detailed an experiment looking into how different participants affect the performance of the haptic system mounted to a seat. It was shown that there was a change in behaviour based on the person using the system. As before, it was shown to be clear that resonance reduction with parametric equalisation is very important.

 

Representation of directional loudspeakers in a finite element room acoustic
The final paper of the session was given by another RS regular, Patrick Macey. The focus of this work was on how to include a directional sound source within a room model. The traditional approach is to replace drivers with equivalent sources along with optimisation, which can be problematic in terms of accuracy. Patrick explained how this can be overcome by using spherical harmonics and then represent it as a point source on a sphere. A simple example was provided, although Patrick noted that for high frequencies, higher order spherical harmonics are needed.

 

SESSION THREE – Hearing health for audio and acoustics professionals (Chair, Adam Hill)
After his extremely interesting and engaging session on hearing health at RS 2023, Ian Wiggins from University of Nottingham, was invited back to lead a panel session to expand upon what he discussed the previous year. Before introducing the panel members, Ian provided a compact review of the human hearing system, how it works and how it can be damaged. Following this, he introduced the panel which included Philip Newell (consultant), Rob Shepheard (NHS), and Simon Lewis (consultant).

 

A focused discussion followed, first looking into hearing testing that is currently available. Philip explained that in the early 2000s, he discovered that he couldn’t hear high frequencies as well as he once could and was also hearing certain elements of distortion, but this was not clearly picked up on standard audiometric tests. Rob agreed with this, saying that such tests are inadequate to assess all types of hearing loss – it’s not enough. The next useful test, that is already given to newborn babies, is the otoacoustic emissions test (OAE), which measures the outer hair cells’ function, providing an early indicator to hearing issues. Additionally, speech in noise testing can be useful to gauge the amount of ‘hidden’ hearing loss, which is common among audio professionals. Despite these additional tests, Rob expressed the need to develop better testing.

 

Simon, who was on the panel representing those with significant hearing loss, gave a brief description of his career in audio and acoustics, explaining that he had to develop coping mechanisms early on as he has relied on hearing aids his entire life. Critical listening with such devices is problematic due to the lack of control of the multi band compression and equalisation that is standard to most modern hearing aids.

 

Philip made clear that in this line of work, it is often difficult to avoid high sound levels and occupational regulations aren’t designed to protect hearing in these situations. Rob commented that the campaign he’s leading, Listen For Life , is specifically for the music industry, providing advocacy, education, hearing testing and information. OAE testing is set to roll out throughout the UK high street this year alongside easily available and affordable high quality hearing protection. This is set to spread beyond the UK with many other countries interested.

 

Ian concluded the session by thanking the panel and expressing a certain optimism that things are moving in the right direction around hearing health in our industry and it’s encouraging to see this topic being more openly discussed than it was only a few years ago.

 

Below: Hearing health for audio and acoustics professionals panel (L-R) Ian Wiggins, Philip Newell, Rob Shepheard, Simon Lewis

 

 

SESSION FOUR – Live sound and venues (Chair, Andy Horsburgh)
Enhanced sound level monitoring at live events using loudness meters
The first paper within the live sound and venues session was delivered by Jonathan Digby from the University of Derby. Jonathan detailed work carried out while working as a sound engineer at several large-scale events, where he found L Aeq -based sound level limits difficult to work with when mixing a band because of the time lag in level data due to measurement averaging over anywhere between five minutes to one hour. In this research, Jonathan trialled the use of audio programme loudness meters that are used in the broadcast industry. Such a meter will monitor the electrical signal coming out of the mixing desk and calibrated to the acoustical output of the sound system to align with any limits in place. The three different time frames in the loudness meter allows an engineer to create a dynamic mix and respond in real-time to any issues, all while complying with an imposed L Aeq limit. He presented data gathered from a selection of recent events, showing how such an approach can benefit sound engineering practice.

 

How to shoot yourself in the foot with arrays of point-and-shoot loudspeakers
The final paper of the day was presented by Glenn Leembruggen, who is another regular at the conference. Glenn discussed a very practical approach to troubleshooting point source loudspeakers on various real-world installations. In one case study, it was revealed that the system showcased low intelligibility and was due to an inconsistent polar response of the point source cluster as well as a high reverberation time in the space. In this case, the angles of the loudspeakers couldn’t be changed, but signal processing was available. Glenn’s approach was to maximise the direct to reverberant ratio and to also add delay between units to increase the density of the comb filtering. This may seem a counterintuitive approach (applying further time offset to the system), but if done correctly, avoiding echoes, it can be quite effective. In the end, Glenn found an acceptable solution using 3ms of delay and seven all-pass filters, significantly increasing intelligibility.

 

Conference reception and dinner
Reproduced Sound’s reception and dinner were held at the Mud Dock Cafe. Delegates enjoyed an evening of networking and catching up with each other. EAG Chair, Ludo Ausiello, once again brought his guitar (which we assume was appropriately optimised) to provide an enjoyable musical accompaniment for the evening.

Conference day two
The second day of RS 2024 began with a special presentation by IOA Past President, Alistair Sommerville. The occasion was the retirement of long-time IOA staff member, Linda Canty. Linda has worked for the IOA for 35 years, providing expert conference organisation with her usual calm and patient demeanour. Specifically, she has been instrumental in the planning and running of most RS conferences. Alistair expressed his sadness to see Linda retire and wished her all the best for the next chapter in her life. He presented Linda with a watch from the IOA and later, Keith Holland presented Linda with a card and voucher from the EAG. The presentation concluded with a rousing ovation from the attendees for Linda.

 

 

Above: Stephen Oxnard delivering his talk

 

SESSION FIVE – Measurement (Chair, Bob Walker)
An internet of sounds-based method for acoustic profiling of rooms and audio spaces
The first paper of the second day was jointly presented by Izzy MacLaclan (Birmingham City University) and John Crawford (Ingenious Audio). The pair described an expansion on previous work on sonifying historic churches. In this case, a system was set up to take simultaneous wireless measurements using a closed WiFi network to improve overall workflow. A description was given of how the hardware works, with suggested future applications of the technology.

 

Characterisation of a resonating system by means of electrical impedance measurement
EAG Chair, Ludo Ausiello (University of Portsmouth) delivered the second paper in the session, which formed the next installment of his work looking into the optimisation of resonating systems, specifically acoustic guitars. Ludo described an affordable test setup to inspect impedance. Results indicated that the exciters did not impact the resonant behaviour of the device under test, so therefore shouldn’t be treated as added mass. A lumped element model was used to confirm the impedance measurements, which provided a clear explanation for the multiple observed resonant peaks.

 

Measurements of multitone distortion in octave bands of a cinema-mixdown loudspeaker system
The final paper of this session was delivered by Glenn Leembruggen. For this paper, Glenn focused on an alternative method for measuring system distortion. Traditional THD measurement signals aren’t like music, therefore he proposed using multitones, as they produce harmonic and inharmonic distortion and potentially serve as more rigorous test signals. In this case, the tones were split into octave bands to allow for easier identification. This was tested in a cinema with the results clearly presented. 

 

 

Above: Glenn Leembruggen delivering his presentation

 

SESSION SIX – Intelligibility (Chair, Paul Malpas)
Word score vs STI tests of a public address system in an underground train station platform
The final paper session before lunch was kicked off by Glenn Leembruggen, this time presenting a case study looking into the rescue of an underground train station’s sound system. The focus was on improving intelligibility to an acceptable standard while not forgetting about the tonal balance – the system should still sound pleasing. The existing system was designed poorly, with inappropriate aiming and signal processing, operating in a poor acoustic environment. Reverberation time was identified as the major problem. While the STI test failed, a PB word test was used with the resulting word scores converted for direct comparison to STI. In this case, it was found that the system passed, allowing the station to open to the public.

 

Multi-channel audio processing for music therapy analysis
Continuing the session on intelligibility was Arina Epure (KU Leuven), who presented on the Unmuted Project, focused on new form of treatment for those with autism. She explained how room acoustics were addressed, using the appropriate standards, along with an onset detection algorithm, which was then tuned to allow a microphone array to monitor sessions in a non-intrusive manner. Early results from trials were presented, offering encouragement for this new approach.

 

Challenges in the assessment of spatial audio in automotive environments
The final paper of the morning was delivered by Bogdan Bacila (University of Southampton) and focused on various hurdles that need to be overcome when designing and conducting subjective assessments for automotive applications. Key challenges include suboptimal loudspeaker placement and highly reflective surfaces, which make for a poor listening environment. Additionally, there needs to be a way to access audio quality in such scenarios, something that the AES is looking into at the moment, with the key being a link between objective metrics and subjective impression. While in situ testing is best, this is often challenging. Bogdan therefore presented his current approach to running such tests, using a tablet for user interface, a camera for headtracking, and methods to eliminate visual bias.

 

EAG AGM
The annual general meeting of the Electroacoustics Group was held prior to lunch and was chaired by Ludo Ausiello. Ludo gave an overview of the activities of the group over the past year, the central focus being the organisation of this conference. He expressed thanks to the committee members for their efforts with the conference planning and specifically thanked Adam Hockley, Andy Horsburgh and the rest of the technical crew for their excellent support on the technical side of the conference delivery. Discussions were held regarding the current committee composition as well as the possibility for new members to join. A conversation was also held regarding the future location of Reproduced Sound, with some options identified.

 

Below: Delegates listening to the presentations

 

 

SESSION SEVEN – Spatial audio 2 (Chair, Keith Holland)
3D auralisation of wind turbine sound for VR
Day two’s afternoon started with a paper by Dan Pope. Dan talked about a recent project concerning wind turbines, where he was tasked with auralising these for use in a VR application. The client brief made clear that a cost-effective solution was required. The solution used ambisonics recordings in typical conditions (which can be difficult to accurately capture). The resulting auralisation was used as part of a public consultation surrounding the replacement of an existing turbine with one with a quieter motor. Overall, the project was successful and the client was happy.

 

A subjective comparison of ambisonics rendered using virtual stereo microphone techniques
Bruce Wiggins from the University of Derby presented the second paper of the session which looked into different virtual stereo microphone techniques within an ambisonics system. This work was prompted by demand from the industry, where it was requested to decode to virtual stereo omni microphones. A series of tests, primarily relying on a multiple stimuli with hidden reference and anchor (MUSHRA) test, were used to judge the overall subjective quality of the resulting virtual microphone configurations. As could be expected, the results indicated that ‘it depends’ in terms of which stereo technique is best, but overall, it was proven that decoding to any arbitrary stereo microphone technique is possible within ambisonics.

 

Radial filter design for open spherical microphone arrays
The final paper of this session was presented by Nara Hahn (ISVR). Nara’s work focuses on the use and optimisation of open space spherical arrays, as opposed to the more traditional rigid spherical arrays. The aims of the array optimisation were efficiency, accuracy and robustness, where there would be one IIR filter for each notch. Additionally, the magnitude response of each filter was limited to less than 40 dB to avoid excessive peaks. The array was tested virtually with time, frequency and spatial performance was evaluated for a beamforming application. The results appeared to be promising, with further work identified.

 

SESSION EIGHT – Diversity presentation and discussion (Chair, Mark Bailey)
Mark Bailey introduced the diversity session at the conference by noting that the conference is still falling short on diversity but there are signs of encouraging progress. Mark reminded delegates that the number one rule for all of this is to be kind. Mark handed over to James Hipperson (Funktion One), who gave a thought-provoking and engaging talk on neurodivergence. He noted that neurodivergence is quite often overlooked but should really be celebrated as it provides diversity of thought within groups. A recent study by the Institution of Engineering and Technology (IET) found that one in five of its members identified as neurodivergent, suggesting that it is much more common in the RS (and wider technical) community than in other areas. As with all items related to diversity and inclusion, it is important to adjust, as appropriate, to improve things for everyone. A lively discussion followed James’s talk.

 

 

Above: Conference dinner at Mud Dock Café

 

SESSION NINE – Signal processing (Chair, Ludo Ausiello)
Complex-valued neural networks for the reproduction of single frequency sound fields
The final paper session of RS started with a paper presentation from Issac Lambert (ISVR), which looked into the issue of spatial aliasing due to microphone grid spacing within wavefield synthesis systems. A convolutional neural network (CNN) was used to help in this area. In this work, the target sound field was compared to the results from both a multilayer perceptron (MLP) and least square error (LSE). All were in agreement at low frequencies, but there were noticeable differences at higher frequencies. Nonetheless, the approach was shown to be effective for single frequencies, but further work is required to inspect it under more complicated scenarios.

 

Sound field analysis using a complex-valued neural network
The final paper of the conference was delivered by Vlad Paul (ISVR). In Vlad’s work, the focus was similar to that of the previous presentation but focused on the reconstruction of a single plane wave. Again, a complex-valued multilayer perceptron (MLP) was used. Even under test conditions with increased aliasing and noise, the results were quite good.

 

Conference close
Reproduced Sound 2024 was formally closed by Ludo Ausiello, who expressed his gratitude to all the presenters, session chairs, committee members and, of course, to the IOA’s Linda Canty for her years of service to the conference, wishing her a happy retirement. The papers were interesting and informative, resulting in a wonderful conference. He specifically thanked the technical crew from d&b audiotechnik and dBS, for their hard work throughout the event. We hope to see you all again in 2025 – bring your friends!

 

Below: Special presentation to Linda Canty on her retirement from the IOA

 

 

 

 

 

 

 

 

 

 

 

Popping balloons can be more harmful than it seems

 

It is hoped that research carried out at London South Bank University on popping latex air-filled balloons for whatever purpose, will influence expert panels, professional bodies and safety regulators to incorporate the new knowledge in relevant future standards, codes of practice and safety advisory labelling.

 

By Dr Luis Gomez-Agustina of London South Bank University

 

Bursting latex balloons filled with air is a convenient method widely employed by acousticians and researchers to generate high intensity impulse sound signals in room acoustics investigations (Figure1).
This approach appears briefly in ISO 354:2003¹ as a potentially suitable impulse sound source for the determination of the room impulse response. The method is extensively employed in acoustic professional practice, education and acoustics research ² - ⁷ due to its portability, convenience, low cost and other practical merits⁸. It is also a common activity performed at entertainment occasions and parties etc but owing to its harmless appearance, fun and leisure connotations, acoustic practitioners and lay users often inflate and burst air-filled party balloons unprotected and unsuspectingly, without being aware of the potential auditory risk that those bursts may have on their hearing health.

 

Below: Figure 1: An air-filled balloon being popped during an acoustic survey

 

 

Rationale, aim and significance of the study
In addition to the intentional puncturing and subsequent bursting, balloons often pop accidentally or unexpectedly. The apparent high loudness and close proximity to the exploding balloon, suggests a potential risk of noise induced hearing loss (NIHL) or hearing damage could occur to the persons inflating, handling or holding and puncturing the balloon, as well as to anyone else present in the room.

The total absence of noise exposure, auditory risk information and lack of safety guidance or standardisation in the execution of the balloon burst method in the literature motivated the investigation into the subject. The potential irreversible hearing damage risk and the large population that can be affected added further motivation and significance to the study. The study aimed to provide for the first time a comprehensive investigation to determine and assess the noise exposure and the risk of hearing damage from bursting air-filled latex balloons as utilised in room acoustics surveys, education and leisure activities. Another aim was to raise awareness and educate acoustic practitioners, professional bodies, and lay users on the associated auditory risks. Derived from its findings, the study provides novel and detailed guidance on safe procedures to be adopted during acoustic measurements or other purposes such as leisure activities.

 

 

Above: Figure 2: Puncturing a large balloon at a distance during acoustic measurements in a lecture theatre

 

Method and materials
The experimental method consisted of taking peak sound pressure level measurements at several distances from the bursts of manually punctured balloons previously inflated with air to the same inflation level. Three suitable hand-held acoustics analysers performed the measurements simulating unprotected human receivers being exposed to the balloon burst impulse sound (figure 2). The test procedure replicated typical test procedures and practices employed by professional practitioners in room acoustics surveys while satisfying the relevant European Directive 2003/10/EC⁹ and UK occupational Control of Noise Regulations 2005¹⁰ test requirements. To examine the effect of the balloon size, three common sizes of commercially available latex party balloons were used and named here in reference to their nominal inflated size measured at the equatorial line: small (23cm), large (38cm) and giant (91cm).

To evaluate the influence of the acoustic environment, three types of rooms of different dimensions, volume, shape, reverberation, absorption and diffusion properties were chosen (a home cinema, a hall of residence lounge and lecture theatre). The combination of the three variables (balloon types, exposure distances and rooms) generated 27 exposure scenarios. (In this article only results for the lecture theatre are shown.) To investigate the effect of the distance between the burst and the receptor’s ear, three measurement distances were used to represent the exposure distances of the person holding and puncturing the balloon at 0.5 metres (reference exposure distance, see figure 1) and of people present in the same room positioned at three metres and six metres from the burst. Three microphones were positioned at the three exposure distances and were connected to calibrated acoustic analysers to measure simultaneously at the three distances levels of L Cpeak and L peak. Measured values were assessed against the limits specified by relevant international occupational noise regulations ⁹ - ¹¹ , ¹² - ¹⁴ to determine the level of exposure and the risk of hearing damage. Based on the values measured and by means of calculation, other relevant information was obtained (presented elsewhere ¹⁵ ) such as the unprotected critical distance, the predicted effect of hearing protection on exposure levels and of estimated exposure to multiple burst events. 

 

References
1. ISO 354:2003 Acoustics - Measurements of Sound absorption in a reverberation room.
2. Iannace, G. and Trematerra, A. (2014) The acoustics of the caves, Applied Acoustics, 86, pp. 42-46.
3. Fausti, P. and Farina, A. (2000) Acoustic measurements in opera houses: Comparison between different techniques and equipment, Journal of Sound and Vibration, 232 (1), pp. 213-229.
4. Abel, J.S., Bryan, N.J., Huang,P.P., Kolar,M., and Pentcheva,B.V. (2010) Estimating room impulse responses from recorded balloon pops, Audio Engineering Society Convention 129, Audio Engineering Society.
5. Iannace, G., Trematerra, A. and Masullo, M. (2013) The large theatre of Pompeii: Acoustic evolution, Building Acoustics, 20 (3), pp. 215-227.
6. Sukaj, S., Bevilacqua, A., Iannace, G., Lombardi, I., Parente, R. and Trematerra, A. (2022) Byzantine churches in Albania: How geometry and architectural composition influence the acoustics, Buildings, 12 (3), pp. 280.
7. Horvat, M., Jambrosic, K., and Domitrovic, H. (2008). A comparison of impulse-like sources to be used in reverberation time measurements, Proceedings of Acoustics2008, Paris, France.
8. Gomez-Agustina, L. and Barnard, J. (2019) Practical and technical suitability perceptions of sound sources and test signals used in room acoustic testing. In INTER-NOISE and NOISE-CON Congress and Conference Proceedings (Vol. 259, No. 2, pp. 7076-7087). Institute of Noise Control Engineering.
Referen
9. European Directive 2003/10/EC (noise). European Parliament and Council 6 February 2003, Minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents.
10. The Control of Noise at Work Regulations (2005), London: HMSO. SI 2005/1643.
11. National Institute for Occupational Safety and Health. (1998) Occupational Noise Exposure, Revised Criteria 1998. DHHS, Cincinnati, OH, pp. 1e105.
12. OSHA (2008) Occupational Safety and Health Standards -1910 Subpart G. Occupational Noise exposure, 29 CFR 1910.95(b)
13. Canadian Centre for Occupational Health and Safety (2015), Noise-Occupational Exposure Limits in Canada. [online].[Accessed 17 December 2024]. Available from https://www.ccohs.ca/oshanswers/phys_agents/noise/exposure_can.html
14. Berglund, B., Lindvall, T., Schwela, D. H. (1999) Guidelines for community noise World Health Organization.
15. Gomez-Agustina, L., Bevilacqua, A. and Vazquez-Barrera, P., 2025. Noise exposure and auditory risk from air-filled balloon bursts. Applied Acoustics, 232, p.110568. https://doi.org/10.1016/j.apacoust.2025.110568

 

 

 

Above graphs: Figure 3: Unprotected exposure levels measured in the lecture room at three exposure distances for three different balloon size types. a) shows values of L Cpeak and b) shows values of L peak

 

Results and analysis
Figure 3 presents balloon burst unprotected noise exposure levels measured in the lecture theatre at three exposure distances. Values shown are the average of 15 bursts of the same balloon size type and error bars denote the corresponding standard deviation (std). Horizontal purple and green dotted arrows in figure 3a indicate the upper and lower L Cpeak action levels respectively (L Cpeak = 137 dB and L Cpeak = 135 dB) for impulsive sound for the unprotected ear of the European Directive 2003/10/ EC (noise)⁹ and the UK Control of Noise at Work Regulations 2005 (Noise Regulations)¹⁰ .

Horizontal red dotted arrows in figure 3b indicate the USA and Canadian occupational health and safety agencies’ maximum permissible limit (L peak = 140 dB) for impulsive sound for the unprotected ear 11-13 . Black dotted arrows in figure 3b denotes the World Health Organization (WHO) 14 maximum permissible unprotected impulse noise exposure level for children (L peak = 120 dB). In figure 3a it can be seen that the large balloon and the giant balloons in the lecture theatre exceeded the Noise Regulations¹⁰ upper action level at the reference exposure distance (0.5m) by 4.8 dB and 0.1 dB respectively. Reaching or surpassing any of the two action levels implies that a risk of hearing damage increases considerably¹⁰ . Figure 3b shows that the large balloon in the lecture theatre surpassed at the reference exposure distance the maximum permissible impulse noise exposure level of the USA and Canadian occupational regulations ¹¹ - ¹³ by 3 dB. Considering the maximum permissible unprotected impulse noise exposure level for children, in figure 3b it shows that level was exceeded at the reference distance by the three balloon sizes between 13 dB and 23dB.

 

Conclusions
Latex party balloons filled with air are widely used in a variety of activities. In acoustic research and professional practice, the burst of the balloon is employed as an impulse sound source to obtain room acoustic parameters. Due to its presumed harmless appearance and leisure connotations, acoustic practitioners and lay users often inflate and pop balloons unprotected and unsuspectingly without being aware of the serious auditory risk that those bursts may entail to their hearing health. This research investigates for the first time the noise exposure from popping air-filled latex balloons for a range of likely settings and assesses the risks of hearing damage against a range of relevant international occupational health regulations. The bursts from two commonly used balloon sizes (large and giant) produced peak sound pressure levels at the ear of an unprotected person holding and puncturing the balloon that exceeded various international occupational health regulatory exposure limits. According to various international occupational health and safety regulations that exceeded exposure from a single ballon burst found in this study constitutes a risk of permanent hearing damage.

 

Children’s maximum unprotected permissible exposure limit was virtually exceeded by the large and giant balloon sizes at all exposure distances in all rooms. Motivated from the concerning findings presented in this study, the authors propose the creation of an international normative to require a prominent safety warning label and/or basic safety instructions to accompany every balloon package as an effective and inexpensive measure to minimise risk of hearing damage from balloon bursts. It is expected that the findings, insights and safety guidance generated in this study will raise awareness, change attitudes and practices of acoustic practitioners and general lay users. This consequently will reduce the risk of hearing damage and aid professionals to comply with applicable occupational health and safety regulations.

 

This article summarises research undertaken at London South Bank University and is based on a journal article published in Applied Acoustics entitled Noise exposure and auditory risk from air-f i lled balloon bursts authored by Dr Luis Gomez-Agustina, Antonella Bevilacqua and Pedro Vazquez-Barrera. The journal article is freely available here https://doi.org/10.1016/j.apacoust.2025.110568

 

References
9. European Directive 2003/10/EC (noise). European Parliament and Council 6 February 2003, Minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents.
10. The Control of Noise at Work Regulations (2005), London: HMSO. SI 2005/1643.
11. National Institute for Occupational Safety and Health. (1998) Occupational Noise Exposure, Revised Criteria 1998. DHHS, Cincinnati, OH, pp. 1e105
12. OSHA (2008) Occupational Safety and Health Standards -1910 Subpart G. Occupational Noise exposure, 29 CFR 1910.95(b).
13. Canadian Centre for Occupational Health and Safety (2015), Noise-Occupational Exposure Limits in Canada. [online].[Accessed 17 December 2024]. Available from https://www.ccohs.ca/oshanswers/phys_agents/noise/exposure_can.html

 

 

 

 

 

 

 

 

 

 

Current parliamentary and policy news

 

Mary Stevens supports the IOA to bring acoustics to the attention of policy makers and this edition’s parliamentary round up covers plans for reforming the way infrastructure is approved.

 

During a busy January the Government announced their promised proposals to reform infrastructure planning, reduce underwater noise and set out a proposal for a land use strategy across England, intended to support the building of infrastructure and homes while protecting nature. Comments on any sound, noise and vibration aspects of the proposals are invited from members.

 

Airports and wind farms included in Government plans to accelerate development
During the last weeks of January the Government made several statements on proposals for changes to the planning process to support their Plan for Change, which is intended to support economic growth by accelerating the building of infrastructure and homes. Working papers on reforming infrastructure planning and a 10 year infrastructure strategy have been published. These are not formal consultations so there is no deadline, but comments are invited. Proposals include overhauling the planning system for major infrastructure projects across England, Wales and Scotland and to ‘streamline’ the approval process for nationally significant infrastructure projects (NSIPs) in England. These include solar and wind farms, electricity networks, roads and public transport infrastructure and water supplies. Many of these developments are subject to noise impact assessments and impact soundscapes. On more specific development a press release announced ‘unlocking’ 13 major offshore wind projects, unleashing an ‘offshore wind revolution’.

 

The announcement refers to targeted changes to the management of underwater noise that will support nature recovery at scale as part of a proposed strategic, rather than site by site, solution to nature recovery. In a series of statements on the forthcoming Planning and Infrastructure Bill the Chancellor Rachel Reeves announced proposals for more homes near commuter train stations and support for expansion of Heathrow airport “in line with UK’s legal, environmental and climate obligations.” The IOA are considering the sound, noise, acoustics and vibration implications of these proposals. We will advocate that these are properly considered for any project in the context of overall Government policy on these issues. Members are reminded that the IOA’s position means we do not take a view about the merits or otherwise of specific projects. Comments from members on the acoustic aspects of the proposals are encouraged – please send asap to mary.stevens@ioa.org.uk

 

See the working papers here: https://www.gov.uk/government/publications/10-year-infrastructure-strategy-working-paper

 

Planning Reform Working Paper: Streamlining Infrastructure Planning – GOV.UK

 

Below: Wind farms are included in Government plans to accelerate development

 

 

Offshore wind noise consultation anticipated
The Government has announced that plans to accelerate the development of offshore wind power will be accompanied by measures to reduce underwater noise. In a press release they stated developers will be required to demonstrate they have made clear efforts to reduce underwater noise from pile driving and clearing ordnance from the seabed during installation of offshore turbines. The Government has partnered with The Crown Estate’s Offshore Wind Evidence and Change programme and representatives from the explosives and offshore wind industries to test and develop new, quieter technologies for bomb clearance, and pilot proposed noise limits during offshore wind construction. It was also stated that a public consultation on setting a future noise limit for offshore wind construction is anticipated with no timeline for this given.

 

Read the full announcement: New measures to curb underwater noise and accelerate renewable energy – GOV.UK

 

England: consultation on land use
As part of ongoing reforms Government have issued a formal consultation on a strategic national approach to land use in England. They say: “The Land Use Framework will provide the principles, advanced data and tools to support decision-making.... This will help deliver the different objectives we have for England’s finite land, including growing food, building 1.5 million homes this parliament, and restoring nature.” Workshops are being held to engage farmers and landowners, and the proposal has been broadly welcomed by conservation groups. The IOA will be responding to the consultation highlighting aspects where acousticians can support land use planning, for example managing impacts of noise pollution from and on any development, and supporting the growth of healthy, vibrant soundscapes. Comments from members are encouraged – please send asap to mary.stevens@ioa.org.uk

 

The consultation is open until 25 April 2025. Land use in England – GOV.UK

 

Comments on future of UK aviation consultation
Questions relating to noise have been answered in the Civil Aviation Authority consultation on the future of UK aviation. We have made several suggestions that would facilitate comparison of noise management performance across airports, in terms of how noise efficient an airport is at providing flights with minimal impact. In addition to reporting the number of people exposed to aviation noise in the UK, the IOA would like to see metrics reported to cover the national noise impact, which will be of interest to track progress to achieve DfT aviation noise policy aims and to assist stakeholders affected by noise from individual airports in understanding their noise, how it has changed and how it is being managed. We would also like to see the number of houses insulated to reduce aircraft noise recorded. In addition, the noise performance of as many airports as possible should be reported, given noise impacts are a location specific local issue.

See the IOA full response here https://www.ioa.org.uk/publications/response-consultations

 

Ireland: EPA consultation on Guidance Note for Noise (NG4)
The Environmental Protection Agency (EPA) in Ireland has consulted on revisions to Guidance Note for Noise (NG4). The draft revision includes updated sections on licence application requirements, including interaction with the provisions of the Environmental Noise Directive agglomerations. It also covers expansion of noise impact assessment using calculation methods and expansion of details required in Environmental Noise Compliance Survey Reports for licensed sites. Also included are updated information and methodologies on measurement of tonal, low frequency and impulsive noise; expanded sections on noise complaints, noise control and mitigation; updates on the assessment of low frequency noise, intermittent noise and other sound characteristics and changes to penalties for noise sensitive locations for both tonal and impulsive noise. The IOA Irish Branch commented on the consultation, which closed 28 February 2025.

 

See the consultation document here https://tinyurl.com/NG4consultation

 

Fireworks Bill introduced to Parliament
A private members’ bill introduced by Sarah Owen MP had its second reading in Parliament in January. The Bill seeks to amend the Firework regulations 2004, to include noise definitions for fireworks, defining a low noise category F2 firework as one with a maximum noise level of 90 dB or lower; and a high noise category F2 firework as one with a maximum noise level higher than 90 dB, and restricting the sale of high noise F2 fireworks. This follows on from a Westminster Hall debate on fireworks sale and use last December. The chair of this debate concluded: “A common theme of all Members’ speeches was that we must push the Government for stronger licensing, noise reduction and restrictions on sale, and for more enforcement powers to be given to our police and local authorities so that they can properly enforce the existing legislation and anything that comes down the line.”

 

See the draft bill here: https://bills.parliament.uk/bills/3791/stages/19048

 

 

Wales: Infrastructure Wales Act 2024
The IOA Welsh Branch provided observations and feedback to the Welsh Government consultation on Implementing the Infrastructure Wales Act 2024. Comments cover noise assessments, environmental health involvement, statutory nuisance, and the pre-application consultation stages. It was also stated that there should be a formal requirement for local environmental health teams to provide input during consultations, particularly on noise and related environmental issues.

 

See the consultation and IOA’s full response here: https://www.ioa.org.uk/publications/response-consultations

 

Below: The impact of transport noise on the reading ability and behaviour of children is the subject of a new research briefing from the European Environment Agency

 

 

New briefing note: acoustic classification of buildings
The IOA have published this new briefing note, making the case for the use of the ISO/TS 19488:2021 framework which defines six acoustic classes for dwellings, ranging from Class A (highest quality) to Class F (lowest quality). This system allows builders to set expectations for acoustic performance and assess the acoustic performance of existing housing, particularly before and after renovations. While building regulations specify minimum acoustic performance requirements for new dwellings, these often fall short in ensuring an adequate living environment and residents still experience high levels of disruptive noise, especially in multi-dwelling buildings. This briefing note highlights the need for a more detailed acoustic classification system that addresses these shortcomings and promotes higher standards of acoustic comfort.

 

Read the briefing note here: https://www.ioa.org.uk/publications/briefingnote

 

 

European Briefing: transport noise impacts on children’s learning
The impact of transport noise on the reading ability and behaviour of children is the subject of a new research briefing from the European Environment Agency (EEA). The report is based on data submitted by EEA member countries under the EU’s Environmental Noise Directive (END). Key findings include that children living or attending school in areas impacted by transport noise tend to score lower on reading comprehension and face more behavioural challenges; over half a million children in Europe experience impaired reading ability due to environmental noise from road, rail and air transport and almost 60,000 cases in Europe of behavioural difficulties in children are due to environmental noise generated from transport. The report concludes that impaired reading ability and behavioural difficulties can be largely prevented through interventions to reduce environmental noise at homes and schools. Interventions outlined include considering noise in planning building orientation, landscaping and engineering measures.

 

Read the full report here: The effect of environmental noise on children’s reading ability and behaviour in Europe.

 

 

 

Mary Stevens

 

 

 

 

 

 

 

 

 

The ANC’s approach to sustainability and acoustics: acoustics industry begins bold and proactive stance on sustainability

 

The Association of Noise Consultants (ANC) recognises that how we design sustainable environments and how we can sustainably conduct our work and run our businesses – is one of the most important and urgent challenges for any modern acoustic consultancy.

 

By Peter Rogers FIOA, and Heulwen Peters, Chair of the ANC Sustainability Committee

 

 

Above: (Lexicon image courtesy of Peter Rogers, Sustainable Acoustics Ltd)

 

The ANC’s Sustainability Committee, formed by a team of consultants volunteering their time and expertise, aims to raise the profile of sustainability within the ANC and beyond.

We are pleased to showcase our series of guides and highlight the documents which will be issued this year. Special thanks must be given to the committee for the hard work, time and effort which they have put in (and continue to put in) to create these resources. You can find the ANC Sustainability Series here: https://www.association-of-noise-consultants.co.uk/resources/sustainability/

 

The ANC welcomes and encourages your thoughts and feedback – please email us at info@theanc.co.uk The documents will be reviewed again between six and 12 months after issue in response to any comments received on them and in line with any new sustainability guidance which the ANC feels need to be incorporated into the documents.

 

Introduction
The ANC’s dedicated Sustainability Committee aims to address the growing intersection between acoustic consulting and environmental responsibility and to guide member companies. This initiative aligns with both the UN’s sustainable development goals ¹ and insights that emerge from the UN Frontiers Report 2022, which identifies noise as one of three key global challenges ² . The ANC’s sustainability framework operates on two critical fronts:
• firstly, it focuses on internal practices, helping member companies develop more sustainable operational methods; and
• secondly, it addresses external client services, ensuring that acoustic consultants provide environmentally and sustainability-conscious design and construction advice, forming part of the solution and delivery of sustainability through the work that they do and the legacy they create, in a quickly changing world. 

 

With the threat of climate crisis demanding immediate and sustained action by companies with purpose and organisations across all disciplines the ANC has ‘grasped the nettle’ to accelerate the positive change needed. It has done this by splitting down the challenge of determining clear and appropriate guidance by considering specific steps on topics that can be taken as part of the bigger journey of humanity to a sustainable future, by which is meant a future that next generations will not be disadvantaged by. This approach responds to the UK Government’s policy on sustainability to baseline emissions and reduce to net zero by 2050. Whilst this is an energy-centric metric the ANC’s vision also emphasises the importance of wider effective action by the acoustics industry in pursuit and promotion of both long-term human health and quality of life; while signposting for member companies how they can begin (or supercharge) their journey to delivering sustainable acoustic practices as part of their net zero journey.

The ANC recognises sustainability as not an optional addition but a fundamental, integrated part of the DNA of modern acoustic consulting, with acousticians playing a vital role in creating a sustainable future. The specific guidance on how to do this by specialist disciplines within acoustics is an evolving picture but by integrating environmental and social considerations into acoustic consulting practices, the ANC has adopted a framework and developed a suite of guidance documents that help to ensure that acoustic solutions contribute positively to broader sustainability goals, while maintaining high standards of acoustic design for clients.

The lexicon provides a lens through which a client’s problem can be considered, beginning with regard for the planet being central in minds as a ‘silent’ client; adding elements of sustainable principles as embedded concepts into the application of the fundamentals of acoustics through to the rim of the lexicon in the particular field of application. The authors of the ANC Sustainability series, and ANC, recognise that each and every user of the documents will have differing experiences, knowledge and views. The language and terminology used within the documents has been peer reviewed by leaders in each topic area, who provide a robust but balanced view in an inclusive set of documents which include differing views from small to large companies. Two documents have been issued so far with more on the way. None of the language within the documents is intended to offend anyone and we don’t seek to represent one view above any other, but a consistent direction of travel and signposting.

The areas that have been identified as the first wave for guidance are summarised below with those in draft also listed:
• sustainability & acoustic consultancy – internal document (in flight);
• quality education (published);
• biodiversity and inclusion (published);
• energy and acoustics (in flight);
• sustainable materials and acoustics (in flight);
• acoustics and sustainable transport (in flight); and
• inclusivity in acoustic design: neurodivergence and aural diversity (in flight).
A short summary of each section by the authors is included below:

 

Internal facing document on sustainability and acoustic consultancy, by Peter Rogers, Pam Lowery, David Hible (in flight)
This document focuses on how acoustic consultancies can become sustainable businesses fit for the future, so that the work they do can be achieved as part of a regenerative system. It proposes guidance for how consultancy business can get their house in order, as the ‘business-as-usual’ model is no longer adequate to justify credible involvement in the delivery of sustainability in practice. The guide emphasises practical ways for companies to play their part by aligning their business models (big or small) with net zero and away from solely a profit-based business, to one based on prosperity that also provides social value and equality, planetary regeneration and biodiversity net gain. By achieving multiple wins the benefits are far broader than those based on the exploitation of resources for profit. This can benefit businesses by resulting in happier, healthier staff, better staff retention, improvement in place and biodiversity at a local level, and a contribution to the national and global solution through the application of science and engineering through acoustics. It sets out how to establish a baseline of the emissions of the business in order to tackle direct and indirect emissions. It also explains the terminology and how to prepare and act on a net zero roadmap, as well as the broader aspects of sustainability that are covered by the UN sustainable development goals and accreditation schemes such as B Corp. This is intended to avoid ‘greenwash’ and provide a defensible and robust pathway for ANC companies fit for delivering acoustic services for a regenerative future.

 

Quality education, by Mat Tuora, Heulwen Peters and Emma Greenland (reviewed)

 

 

The ANCs quality education guide focuses on approaches to education design which, in the view of the group, best serve sustainable design objectives and meet acoustic objectives. UN Sustainable Development Goal 4 asks us to ‘ ensure inclusive and equitable quality education and promote lifelong learning opportunities for all’ . The guide recognises a need to provide a holistic approach to education design which is accessible and inclusive, whilst meeting usual acoustic design objectives and satisfying clients’ desires and needs.

The guide signposts and builds on recognised and developing guidance for education design. It aims to support acousticians with an understanding of common acoustic considerations needed to fulfil optimised education design sustainability objectives, such as consideration of learning differences, aural diversity and the wide range of users who need to and want to access education facilities.

 

Biodiversity in acoustics, by Reena Mahtani, Mat Tuora and Jo Hughes (reviewed)

 

 

The biodiversity in acoustics document discusses the impact that acousticians can have when considering strategies on the requirement to protect and restore natural habitats to enhance biodiversity and mitigate climate change. Natural soundscaping and habitat creation are discussed alongside strategies for noise mitigation, in addition to incorporating ecological features like earth bunds and planted façades in the design to provide habitats for local wildlife. It also acknowledges that additional input from other disciplines is necessary for this approach to be successful as part of a cross-collaboration effort.

 

Energy and acoustics, by Peter Rogers and Barry Joblin (in flight)
This guide aims to explore how acoustics can be central to the delivery of the renewable energy transition, with regard for supportive infrastructure including wind turbines, solar farms, air source heat pumps and other aspects which make energy generation in the UK, its provenance and security a government priority. It is important to recognise that acousticians also have an important part to play in the sustainability of energy production systems when sited close to communities, and how, through good acoustic design, their impact on residents and businesses can be limited.

 

Sustainable materials and acoustics, by Clement Luciani, Mat Tuora, Vince Taylor and Momo Hoshijima (in flight)
This guide aims to raise awareness of the options available to inform, promote and specify more sustainable alternatives to conventional construction materials and products. The guide introduces the core aspects of sustainability being considered by the industry for building materials and how they are assessed and compared, highlighting the complexity of the task and the lack of standardised methodologies.

Three overarching strategies are presented and discussed to reduce the environmental impact of building materials:
• avoiding unnecessary extraction and production (circularity);
• shifting to regenerative bio-based materials; and
• decarbonisation of conventional materials.

 

The role acousticians can play within each of these strategies is discussed and suggestions for next steps made.

 

Acoustics and sustainable transport, by John Fisk (in flight)
Our guide on acoustics and sustainable transport starts with discussion of the noise impacts of the three most popular transport modes (road, rail and aircraft) and how these affect health and wellbeing. It then points to current practice methods for assessing the impacts and briefly presents ways to control these noise impacts. Noise control methods will generally also have adverse and beneficial impacts on aspects other than acoustics (e.g. economic, cost, energy efficiency, visuals and ecology etc.) This is discussed along with some examples and how the overall sustainability of a control method might be weighed up given these competing interests. The guide finishes with a look at how transport modes might change in a more sustainable future and how this might affect the noise environment around them and planning decisions made.

Inclusivity in acoustic design: neurodivergence and aural diversity, by Reena Mahtani, Mat Tuora (in flight), Joshua Yardy (review comments)
The inclusivity in acoustic design guide is focused on acoustic design for individuals and provides a short introduction to the concept of aural diversity and its application in practice. The intention of the guide is to promote that everyone’s auditory experience is unique and emphasises the importance of considering these differences in the design of spaces to ensure inclusivity and accessibility for all. It is widely known that robust acoustic design can mitigate the sensory sensitivities experienced by some individuals and enhance the functionality of spaces. The guide includes a review of the guidance already available on the topic and summarises some basic considerations that should be considered during the design of spaces. The importance of balancing the acoustic design in conjunction with other disciplines, such as lighting, to create truly inclusive and supportive environments is also mentioned to achieve a truly inclusive design.

 

 

Conclusions
A start has been made with this suite of guidance to help ANC companies rise to the challenge of our age. They signpost a consistent way forward and suggest ways that positive action by acousticians can be taken to deliver sustainability through the work they do, and to get their house in order as companies fit for the future.

 

References
1. UN Sustainability Development Goals, https://sdgs.un.org/goals (accessed 3/2/25)
2. UN Frontier Report 2022 – Noise, Blazes & Mismatches, https://www.unep.org/resources/frontiers-2022-noise-blazes-and-mismatches (accessed 3/2/25)

 

 

 

 

 

 

 

 

Questioning the quality and accuracy of noise assessments of battery energy storage systems

 

As those consultants working in the renewables industry will know there has been a rapid rise in applications for battery energy storage systems (BESS) over the past few years, either as stand-alone or attached to solar or turbine developments. Noise consultant, Dick Bowdler, has reviewed about a dozen noise assessments for these systems and, in this letter, voices his concern over their quality and accuracy.

 

 

There are three problems: the poor quality of manufacturers’ information, the technical accuracies of the calculations and the variety of assessment methods. I will outline the issues in a bit more detail in the hope that it will lead to improved quality and accuracy of assessments.

 

Taking manufacturers’ information first, it is perhaps no surprise that with new plant being developed at a fast rate, manufacturers do not produce good quality data until a range of models has been established. However, it is as much in the developer’s interest as anyone else to get good data because it reduces the commercial risk and it is also very much in the consultant’s interest to get it as accurate as possible for obvious reasons. Noise data are almost all of low quality (and hence, high uncertainty) or simply absent. Most of the data that are available are presented as 1m (or some other distance) from the equipment. For example, the sound pressure level of a transformer 9m by 6m by 6m is quoted as 68 dB at 2m. This really tells us very little. Is that the level at the one noisy part of the transformer, or the average level at 2m all over the transformer, or is it the average of a few spot measurements? Some manufacturers provide no noise data at all and hardly any provide frequency spectrum data. Others provide data under an NDA so it becomes more difficult to verify that it is valid.

On my second point on the accuracy of the calculations, in the transformer example above, the consultant simply converted the 68 dB at 2m to 82 dB SWL. That treats it as a point source with hemispherical propagation. Of course it is extremely unlikely that it is a point source as it would only be so if all the sound from the transformer came from a single point 2m from the microphone and none from anywhere else on the transformer. If the sound was equally emitted from all over the transformer at 68 dB at 2m, the SWL would be about 94 dB. Unfortunately, using point source calculations where it is clearly not a point source is still common and will most likely under-estimate the noise at sensitive receptors very significantly.

On my final point of the assessment method, nearly all of the assessments say how wonderful SoundPLAN or CADNA is, as if their use means the result must be correct. Some assessments discuss uncertainty in the calculations of ISO 9613 but not one of the assessments that I have seen discusses the uncertainty of the input data. Hardly any assessment put a comprehensive list of the inputs. The guidelines for assessment are certainly inadequate and this is apparent from the methods put forward. In one case, a specific noise of 44 dB with background level of 26 dB in the evening is low impact and minor adverse. In another a specific noise of 31 dB compared with 25 dB background is rated as high impact. Almost everyone focuses on BS 4142 but most also mention or use one or more of BS 8233, WHO Enger, WHO night guidelines, NR curves. In fact, in some instances, the reader might be forgiven for thinking the assessor had gone through all the guidelines in turn to find one that worked. Some sort of coordinated agreement is needed to create an element of standardisation. Maybe BS 4142 is the correct approach but there is certainly widespread agreement that, at low noise levels, an absolute level is more realistic. How this latter point is dealt with is the crucial matter.

 

I’ve avoided introducing my personal view so far, but I would like to make one comment, that any use of BS 8233 is not appropriate. Since its origin as Chapter III of CP3 in 1972 it has always been about the design of sound insulation of buildings. It is nothing to do with industrial developments affecting existing houses. The Scope of BS 8233:2014 says it ‘… does not provide guidance on assessing the effects of changes in the external noise levels to occupants of an existing building.’

 

To summarise:
Assessments should be transparent. Where data is inadequate consultants should attempt, or ask their clients to attempt, to get better data. Failing that the inadequacy of the data should be clearly described. Make sure your calculations are right. Failing any agreed assessment method, each consultant needs to consider what their own view is and, of course, use the same method on all similar projects. The assessment method should be clearly defined at the start of the assessment.

 

Dick Bowdler

 

 

Response to: Questioning the quality and accuracy of noise assessments of battery energy storage systems

 

I read with interest the letter from Mr Bowdler regarding the prevalence of battery energy storage system (BESS) planning applications in recent times (page 59 of this issue) and respond as a member of the IOA’s Renewable Energy Advisory Group (REAG). Please note this is my personal response and does not represent the REAG as a whole.

 

Within the REAG we have a sub-group, which has been formed to focus on producing a good practice guide (the Guide) for the assessment of noise from BESS and solar developments.

 

The formation of the sub-group was presented in a wider paper regarding the REAG at the Acoustics 2024 conference, which was subsequently summarised in Acoustics Bulletin Nov/Dec 2024. The Guide is still in its preliminary stages but the group has already expressed similar concerns to Mr Bowdler and we hope that when it is published it will help to normalise the approach to noise assessments for such developments. In particular, we share Mr Bowdler’s concerns over the use of manufacturer supplied noise level data, both in the quality of the data that is published and in the various approaches that consultants attempt to use it.

One of the most significant problems we perceive, is that of a lack of knowledge about how a BESS site (and similarly related solar plant) actually operates, both in terms of layout design, and in respect of operating parameters and related noise output. In terms of layout, this includes: what plant is required, how many batteries and inverters do you need for a particular capacity and how does that vary by manufacturer, what is the difference between a two-hour storage facility and a four-hour storage facility? Maybe most critically, how can we be sure that appropriate candidate plant is being specified and how does that affect the required layout? In terms of operation and noise, this is particularly complex; when do cooling fans start to operate, is cooling based on load or ambient temperature (or both), is more noise generated during charge or discharge cycles, and often the most difficult question, what do I do with this poorly presented source noise level data? This lack of knowledge is not just present at the acoustics consultant level, but also within councils (many of whom treat BESS the same as substations), and even for the developers themselves. Accordingly, the Guide will seek to provide guidance, not just through purely acoustics assessment terms, but also by introducing the reader to what makes up a typical BESS (and solar) layout, how the noise output might vary depending on plant specifications, layout and operation, and what mitigation options are available (and realistic).

 

I hope that the Guide will also encourage manufacturers to ‘up their game’ when it comes to providing source noise level data and encouragingly, Over the past 12 months or so, I have seen noise being taken more seriously by some manufacturers. At TNEI, we have undertaken ISO 3744 measurements for several plant suppliers, who now have 1/3 octave sound power level data for each façade and top of their battery and/or inverter units, operating at various different fan capacities and similar, and that is the type of data that the Guide will seek to encourage plant manufacturers to provide to consultants and developers. The fact is, however, that currently many manufacturers do provide sub-standard noise level data, so the Guide will need to demonstrate how to manage this data, how to consider uncertainty (both for the noise data and the operational status of the plant), and how best to use this within a noise model.

The Guide should also encourage manufacturers to provide more detailed noise and operational data, penalising, for example, the use of noise data without accompanying operational data, by assuming that all plant is always operating at 100% capacity (and maximum noise level output). I am sure Mr Bowdler will remember a time when wind turbine noise level data was provided in a multitude of formats and of varying degrees of quality, though nowadays, thanks to standardised measurement procedures and in no small part to the publication of the IOA GPG¹, the way that wind turbine noise level data is considered within assessments in the UK is generally agreed upon, and a common approach to modelling has been adopted. I do hope that we will get some way there soon for BESS plant and similar.

With regards to the use of BS 8233 and other standards and guidelines that sometimes seem to be adopted inappropriately, I am not sure that is isolated to just BESS noise assessments and I personally share similar concerns to how and where these ‘guideline levels’ are used more generally for industrial and commercial noise assessments. I expect the proposed changes to BS 8233, if adopted, will help to alleviate this issue somewhat. We now have enough people within the sub-group to produce the Guide, however, I have invited Mr Bowdler to join the wider peer review team and if other IOA members are also interested in being part of the peer review, then please feel free to get in touch.

 

Jim Singleton
jim.singleton@tneigroup.com

 

1. A good practice guide to the application of ETSU-R-97 for the assessment and rating of wind turbine noise