PERCEPTUAL EVALUATION OF THE BS 4142:2014 PENALTY METHOD FOR MULTIPLE SOUND CHARACTERISTICS

PERCEPTUAL EVALUATION OF THE BS 4142:2014
PENALTY METHOD FOR MULTIPLE SOUND
CHARACTERISTICS ☁
C Youdale University ofSalford. M5 4WT. UK"
J Woodcock University of Salford. M5 4WT. UK
D Waddington University ofSalford. M5 4WT. UK"
'Current address: Amec Foster Wheeler, Warrington WA3 6GN
☜Corresponding author: d.c.waddinglonsalford.ac.uk (d[dot]c[dot]waddinglon[at]salford[dot]ac[dot]uk)
ABSTRACT
The aim of this paper is to evaluate the BS 4142:2014 penalty method for multiple sound
characteristics. BS 4142:2014 is one of the most widely used standards. and is used for rating and
assessing industrial and commercial sound. It contains a graduated approach to sources containing
multiple characteristic features where tonal. impulsive and intermittent characteristics can be
considered separately and corrections applied cumulatively to sources that contain more than one
of these characteristics. Whilst there is good evidence to show an increased annoyance response
to sound with tonal, impulsive or intermittent features. there has been little research performed on
the response to sound containing multiple characteristics, suggesting that the application of linearly
applying penalties has little perceptual basis. To assess the validity of this linear summation of
penalties, an annoyance matching experiment was performed. The stimuli consisted of seven
samples of an industrial broadband fan noise that had-been modied to introduce tonal. impulsive
and intermittent characteristics. Seventeen subjects adjusted the levels of each sample to match
the perceived annoyance of a reference. The results indicate that the annoyance response to a
sound containing multiple characteristic features is not well represented by linearly summing
penalties for each characteristic feature. This suggests that further research is required to provide
the scientic basis for additional guidance on the linear summation of penalties in ES 4142:2014.
1 INTRODUCTION
BS 4142:2014 took a signicant departure from the now superseded BS 4142:1997 in its approach
to applying a characteristic penalty to sources containing multiple features. In the previous
standard. a rating level for a source containing characteristics could be obtained through applying a
subjective penalty of 5 dB. regardless of character prominence or how many characteristics a
source might contain. The latest iteration of the standard now contains a graduated approach to
sources containing multiple characteristic features. where tonal. impulsive and intermittent
characteristics can be considered separately and corrections applied cumulatively to sources that
contain more than one of these characteristics. This paper aims to assess the perceptual validity of
the linear summation of characteristic penalties through presenting and discussing the results of an
annoyance matching experiment that was performed at the University of Salford.
2 PREVIOUS RESEARCH
Negative effects of noise on human health and behaviour are well documented. These range from
the auditory health effect of noise-induced hearing loss to other non-auditory health effects such as
disturbance of sleep, hypertension and ischemic heart disease☁- 2. The non-auditory health effects
are often responses to what is the most widespread community response to environmental noise;
namely annoyance☂. which has been identied as the main effect of environmental noise☁.
Predicting annoyance caused by noise is a complicated problem. as it has been shown that human
reaction to noise is more than just a purely psychoacoustic problem. Psychological and
environmental variables must also be taken into account. (such as state of anxiety. personality.