ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

5aNS10. Effect of silent periods having short or long durations on the annoyance of vehicle sounds.

Niek J. Versfeld

Joos Vos

Frank W. M. Geurtsen

TNO Human Factors Res. Inst., P.O. Box 23, 3769 ZG Soesterberg, The Netherlands

Two laboratory experiments were performed to study the effect on annoyance of noise concentration in time. The first (rating-scale) experiment dealt with the influence on annoyance of short-time silent periods (varying from 0 to 160 s) in pass-by vehicle noise of 240-s total duration. Results showed that, at a fixed equivalent sound level, and with the number of vehicles kept constant, annoyance hardly depended on the duration and position in time of the silent period. In the second experiment subjects had to compare the annoyance of road traffic sounds with that of sounds from heavy vehicles (such as tanks). In deciding which fragment was more annoying, the subjects had to imagine that they were exposed to the road traffic sounds throughout the year, whereas the sounds of heavy vehicles were only audible during a certain part of the day, week, or year. Results indicate that, at a given equivalent sound level, concentration of the sounds in time reduces annoyance. [Work supported by the Ministry of Defence.]