Road traffic noise annoyance in relation to average noise level, number of events and maximum noise level

The extent of annoyance caused by road traffic noise was investigated in 15 areas with a varying number of vehicles and different distances between the traffic and houses. The goal was to compare two principles for expressing noise exposure. One was based on the conventional energy equivalent value in terms of a 24-hour L-Aeq value. The other was based on the number of events and noise level as two independent variables. A postal questionnaire study was performed in the different areas, and noise exposure measurements were made at a representative site in each area. The individual noise exposure was calculated on the basis of the distance of the respondent from the road and the floor level. The results showed that the number of noise events did not influence the extent of annoyance. There was a strong relationship between the L-Aeq and the extent of annoyance as well as between the maximum noise level and the extent of annoyance. These data suggest that actions to control the disturbing effects of road traffic noise should focus on noisy vehicles and that limiting the number of vehicles would not have an effect;on the extent of annoyance. (C) 1999 Academic Press.