Loudness of an auditory scene

Abstract

When multiple sound sources, each of equal level, are added together to create an auditory scene, the overall level of the scene grows with the increased number of sources despite the fact that the level of the individual sound sources remains the same. This experiment addresses a simple question: how does the overall perceived loudness of an auditory scene change as the number of sound sources in the scene changes. Sixteen Consonant-Vowels (CVs), spoken by ten males and ten females, were the sound stimuli. The CVs could be concatenated to produce nonsense “words” of different lengths. Different number (“n”) of concatenated CVs could be presented at one time from a single loudspeaker located on the azimuth plane or from different loudspeakers. Listeners determined if “n + delta n” sound sources were louder than “n” sound sources. The individual levels of the concatenated CVs was another independent variable. Preliminary data suggest that when “n” is small (<4), the level of the individual sounds determines loudness judgements. When n is larger (n>4) the overall level of the simultaneously presented sounds determines loudness judgements. A full study will be presented. (Work supported by grants from NIDCD and Oculus VR, LLC.)