Perceptual Relevance of Speaker Directivity Modelling in Virtual Rooms
* Presenting author
Sound sources like a human speaker, musical instruments, and loudspeakers typically radiate sound with a frequency-dependent directivity pattern. If a human speaker faces the receiver, more high-frequency components reach the receiver as when the speaker turns in the opposite direction. This is perceptually easily detectable, particularly in anechoic conditions. In rooms, early reflections and late diffuse reverberation, which both can be differently affected by the directivity pattern of the source, occur in addition to the direct sound. While source directivity appears relevant for distinct early reflections, it is unclear to which extent the perceptual effects average out for later reflections and diffuse reverberation.Here we assess to what extent directivity of a human speaker should be modelled for early reflections and diffuse reverberation. For this we used a hybrid approach to simulate and auralize binaural room impulse responses [Wendt et al., JAES, 62, 11 (2014)], combining an image source model (ISM) for early reflections with a feedback delay network for diffuse reverberation. The approach was extended by a directivity filter based on a spherical head model. Listeners distinguished between source orientations solely based on ISM-directivity and detected average source directivity filtering even in reverberant conditions.