Subjective diffuseness of music signals convolved with binaural impulse responses

The spatial impression of sound in a hall can be quantified using sound field factors such as the interaural cross-correlation coefficient (IACC) calculated from binaural impulse response (BIR), henceforth denoted by IACCIR. The subjective diffuseness for the listener is a spatial attribute which depends on factors associated both with the source signal and with the actual sound field, and is quantified using the IACC of the signal received by the listener, henceforth denoted by IACCSR. Therefore, the subjective diffuseness in a given hall may change with the music. The aims of this study are to estimate the IACCSR from the IACCIR and the factors, which is obtained from autocorrelation function (ACF) of music signal, and to evaluate the subjective diffuseness by these factors. First, the relationship between the IACCIR and IACCSR was investigated. Second, subjective diffuseness was measured by a psycho-acoustical experiment. As a result, the IACCSR could be estimated from the IACCIR of the BIR and the effective duration (τe) from the ACF of music signal. It was found that the effects of BIRs on subjective diffuseness could be evaluated by IACCIR for almost all subjects, while the effects of music signals could be evaluated by the τe and the width of the peak at τ=0 (Wϕ(0)) of the ACF.