Throughout this paper, the term ‘Sound Systems for Emergency Purposes’, SSEP, will be used to include ‘Emergency Communications System’, ECS, as defined in NFPA72:2016 and ‘Voice Alarm Systems’, VAS, as defined in BS EN54-32:2015 and BS 5839-8:2013. The SSEP industry constantly evolves due to the implementation of newer technologies. The motivation behind these developments are often attributed to emerging “green” requirements to be energy efficient and space saving to provide physically smaller systems thereby freeing up precious real estate.