How to measure the degree of interaural cross correlation as a physical factor for auditory source width

The degree of interaural cross correlation is well known as a physical factor for auditory source width (ASW). But, how to measure it is not yet described clearly. The degree of interaural cross correlation obtained by using a dummy head with an artificial ear simulator cannot explain the results by Barron and Marshall [J. Sound Vib. 77, 221–232 (1981)]. But, the degree obtained by using a dummy head without an artificial ear simulator can explain the results. Furthermore, it is impossible to explain ASW of stimuli that include the high‐frequency components (higher than about 1.5 kHz) even if the latter degree is adopted. Finally, this paper proposes auditory processed interaural cross correlation (APICC) (the degree of interaural cross correlation obtained in consideration of the mechanism of binaural signal processing) as a physical factor for ASW.