Relative distance perception of sound sources in critical listening environment via binaural reproduction

Georgiou, F

Abstract

Accurate distance cues are important in the degree of realism provided by virtual audio systems. In the last decade there has been an increased interest in this research area. The main focus of this research project is to investigate the effect of different acoustic cues related to distance perception, such as Direct to Reverberant ratio (D/R), in the perception of the relative distance between sound sources in a virtual medium sized critical listening room. The virtual sources were generated by convolving a dry speech signal with modelled and measured BRIRs. The BRIRs were modelled using a direction related image source model for the early reflections and exponentially decaying noise for the reverb tail. In order to investigate relative distance perception and the factors that affect it, a pairwise comparison was conducted involving twenty- three subjects. Three different distances ranging between 1.0m and 3.0m were used in the comparison pairs. The main outcomes from the tests are: 1) Modelled and measured BRIRs provide relative distance cues equally well; 2) Direct-to-reverberant ratio is a significant relative distance cue, even when level between virtual sources is normalized; 3) Adding level differences between the sources does not have a significant effect on the perception of relative distance. However, it reduced the precedence of wrong relative distance judgments by 5%-15%; 4) Manipulation of early reflection time of arrival (TOA) does not appear to be a significant cue in distance perception. These findings are important in the field of virtual reality and computer gaming because they show that the relative distance of a virtual source can be manipulated simply by adjusting the direct-to-reverberant ratio of the BRIRs. It can thus be concluded that large BRIR databases and interpolation between BRIRs at different distances are not required for appropriate distance cues.

Citation

Georgiou, F. (2012). Relative distance perception of sound sources in critical listening environment via binaural reproduction. (Dissertation). University of Salford

• Thesis Type: Dissertation
• Deposit Date: Feb 2, 2018
• Publicly Available Date: Feb 2, 2018