Subjective response to road traffic noise

Abstract

A study consisting of acoustic measurements at fourteen sites in the London area and 1200 interviews dealing with the effects of the noise conditions prevailing at each of these sites has been carried out with the object of developing acceptability criteria for traffic noise from roads in residential areas. Dissatisfaction with the noise conditions, as expressed by residents at each of these sites, was related to sound levels in such a way that it was possible to predict the median level of dissatisfaction at each site by the use of a measure taking into account the mean sound levels exceeded for 90 and 10 % of the sampling periods throughout a whole day, which it is proposed to call the Traffic Noise Index (T.N.I.). Predictions made on the basis of either 10 or 90 % levels alone were considerably less accurate than those made on the basis of the combined measure. Individual dissatisfaction scores correlated poorly with physical measures. This finding is believed to be the result of wide individual differences in susceptibility to and experience of noise, as well as in patterns of living likely to be disturbed by noise. Attempts to allow for these factors were unsuccessful. Disturbance of various activities was shown to be related to noise levels and the increasing extent of this effect with worsening of noise conditions was used to validate the scale of dissatisfaction.