Subjective salience and the effects of familiarity with birdsongs and insect songs in noise environments

Abstract

In Japan, birdsong is used to communicate the position of stairwells to visually impaired people at train stations. However, more than 40% of visually impaired people reported that such sounds were difficult to identify. Train companies seek to present sounds that are loud enough to be detected, but not loud enough to cause annoyance in noise environments. In this study, we examined the salience of different types of bird and insect songs in noise environments. We evaluated the subjective saliences of bird and insect songs with equal sound pressure levels using paired comparison methods. A total of 25 participants evaluated six types of bird and insect songs under three noise conditions. The relationships among subjective salience, physical parameters, and familiarity were examined. The results indicated that the sounds of Horornis diphone and Meimuna opalifera were the most salient types of birdsongs and insect songs, respectively, in noise environments. The degree of temporal and spectral change, binaural similarity, pitch, pitch strength, and familiarity were significant predictors of the subjective salience of birdsongs and insect songs in noise environments.This study contributes to enhance the safety of visually challenged people and to create a more attractive sound environment.