Utilizing head movements in the binaural assessment of room acoustics and analysis of complex sound source scenarios

Abstract

The measurement of transfer functions is currently standard practice for the acoustic evaluation of performance venues. The pathway between a measurement loudspeaker and a microphone or binaural manikin in a room can be treated as a linear time-invariant system, and meaningful acoustical parameters can be derived from measured impulse responses. Unfortunately, this method neglects that human listeners typically move their heads when exploring an acoustic venue. This paper addresses these implications when designing systems to take head movement into account. A number of approaches will be discussed based on existing research and technology at Rensselaer, including a binaural manikin with a motorized head, a technique to simulate head movements from impulse responses recorded with a higher-order spherical microphone, and a binaural model that can process head movements. The model distinguishes between a room coordinate system and a head-related coordinate system. Its binaural activity map is rotated with head movements in order to separate front-back images, resolve the reverberation-reduced angle of lateral sound sources, assess different surround loudspeaker configurations for immersive sound systems, and separate acoustic sources. The research presented here has received support from the National Science Foundation under Grant No. 1002851.