Abstract
In this study, we investigated the influence of the distribution of sound-pressure levels (SPLs) on subjective loudness of environmental noise. To investigate the influence, subjective-loudness evaluation test was performed using road-traffic noise having various distributions of SPL. Skewness was used to evaluate the SPL distribution. Our results show that the loudness of the presented sound was perceived to be softer when the skewness was largest at 0.8 (the frequency of low SPL was high), even though the equivalent continuous A-weighted sound-pressure level (LAeq) was almost the same for all samples. On the other hand, the subjective loudness did not change significantly in the other conditions (the frequency of low SPL was low). From the result, the subjective loudness was found to decrease at a specific condition when the frequency of low SPL is high.
