Adjusting the Perceived Distance of Virtual Speech Sources by Modifying Binaural Room Impulse Responses

Effective control of the perceived location of virtual sound sources is an important aspect of auditory displays. While room acoustics modelling may be used to produce cues related to the sound source and listener location in a space, in many real-time applications it is more feasible to utilize ready-made room impulse responses. This paper looks at how the perception of distance can be affected by modifying the temporal envelopes of room impulse responses. Two measured binaural room impulse responses were modified by amplifying or attenuating different portions of them before convolving them with speech samples. Listeners were asked to judge the relative distances between these virtual speech sources presented over headphones. The results suggest that the perception of distance is more effectively altered by modifying an early-tolate energy ratio, where approximately 50–100 ms of the impulse response is included in the early energy, than by directly modifying the traditional direct-to-reverberant energy ratio.