Sound image broadening by a single reflection considering temporal change of interaural cross-correlation

摘要

In this paper, we study the width of a sound image due to the combination of a leading sound and its delayed one, each coming from different directions. If the loudness of the leading and the delayed sounds are the same, the sound image is localized in the middle between the leading and the delayed sounds. However the sound image is rather spread out in space (broadened). This can, e.g., be experienced in car-stereo listening by the off-center listening position. This study concerns auditory experiments as well as an analytic model of the broadening effect. A pair of noise bursts was used as the leading and the delayed sounds. To express the width of the sound image, the ICC (interaural correlation coefficient) of noise bursts made from two incoherent noises is introduced. The width of the sound image increases as the delay time between the leading and the delayed sounds increases. For delays longer than 10 ms, it reaches subjective diffuseness. The ICC represents this subjective diffuseness caused by the leading and delayed sound better than the TRICC (maximum value of a normalized transient interaural cross-correlation function) or the IACC. [References: 16]