Appropriate frequency bandwidth in measuring interaural cross-correlation as a physical measure of auditory source width

Abstract

There has been a demand for measuring the degree of interaural cross-correlation (ICC) as a physical measure for auditory (apparent) source width (ASW). Standardization of the measurement has been also discussed by ISO. One of the important problems in measurements of ICC is the selection of frequency bandwidth. Following ISO, ICC is defined with a wide frequency band and generally measured in 1/1 octave bands. This paper reports two experiments that compare ASW with ICC measured by different methods, so as to determine the best physical measure in terms of correlation with the subjective effect. The experimental results show that the use of 1/3 octave bandwidth is preferred to the use of a wide bandwidth and 1/1 octave bandwidth for measuring ICC as a physical measure of ASW.