Loudness of a multi-tonal sound field, consisting of either one two-component complex sound source or two simultaneous spatially distributed sound sources

Abstract

The aim of the present study is to provide new elements about the perceived loudness of stationary complex sound fields and test the validity of current models under such conditions. The first part consisted in testing the hypothesis according which the directional loudness of a multi-component sound source could be fully explained by the directional loudness of each of its single components. In this way, the directional loudness sensitivities of a two-component complex sound source (third-octave noise bands centered at 1 kHz and 5 kHz) have been measured in the horizontal plane. Despite a previous equalization in loudness of each component to a frontal reference, a small effect of the azimuth angle on loudness still remained, partly disproving the assumption. In a second part, the influence of the spatial distribution of two sound sources on the global loudness was investigated (with the same two narrow-band noises). No effect has been found by Song (2007) for small incidence angles (10 and 30°). The present experiment extends this result for wide incidence angles and so, under highly dichotic listening situations. Finally, all the subjective data have been compared with the predictions from different models of loudness, and the results will be discussed.