Inter-aural cross correlation in a sound field represented by spherical harmonics.

Abstract

Spaciousness is an important acoustic feature of concert halls. An accepted measure for spaciousness is the inter-aural cross-correlation (IACC), which employs the transfer function from a source in the hall to the two ears of a listener, the latter referred to as head-related transfer functions (HRTF). Recently, spherical microphone arrays have been studied for room acoustics analysis and music recordings. As these arrays typically use a finite number of microphones, they may not be able to capture the spatial information required for complete spatial analysis or for sound reproduction with realistic spaciousness. This study proposes the use of spherical harmonics representations for both the HRTF data and the sound field data, facilitating IACC analysis for sound fields represented by a finite order in the spherical harmonics domain. The effect of limited spherical harmonics order on the spaciousness of various sound fields is finally studied using simulated and measured data.