Influence of manipulated early reflections on room acoustical perception

Abstract

The binaural room impulse response (BRIR) can be used to study the perception of room acoustics and consists of different parts such as the direct sound, early and late reflections, and a diffuse reverberant tail. For this study, the contribution of early reflections to several perceptual attributes was investigated. For this purpose, the strength of the early reflections of recorded BRIRs were either increased or decreased. The resulting BRIRs as well as the original BRIRs have then been convolved with anechoic music signals to obtain the stimuli that were presented to the subjects in a psychoacoustic experiment. The subjects had to rate the spatial impression of these manipulated and none-manipulated signals for the perceptual attributes “Listener envelopment,”” Apparent source width,” “Distance” and “Presence.” In addition to determining the influence of manipulated early reflections on the spatial impression of a room, also a comparison was made with the perceptual effect of an artificial increase of the interaural cross-correlation. Results indicate that the perceived source width increases with increasing level of the early reflections. The effect of the level manipulations on the listener envelopment seems to be small compared to the influence of the cross-correlation.