通路相位差、信号频谱与立体声声象宽度

Interchannel Phase Difference,Signal Spectrum and Stereo Sound Image Width

本文利用重发通路间存在相位差时的立体声声象定位公式，定量地探讨了声象宽度与通路相位差、信号频谱之间的关系，并进行了实验验证。理论和实验结果表明，随着通路间相位差的增加，声象随信号频带宽度的增加而展宽。利用耳间相关系数ＩＡＣＣ对声象进行了理论分析，结果表明，随着通路相位差的增加，ＩＡＣＣ随信号的频带宽度的增加而下降，因而导致声象明晰度下降，利用耳间相关分析，还得到立体声重发时，展宽声象的“中心”位置。文中指出，为了保证重发确定位置且明晰的声象，在实际应用中应尽可能地减少通路间的相位差。

In this paper,by using the stereo sound image localization equation,at phase difference,existing between the reproduction channels,the relationship among the sound image width,interchannel phase difference and signal spectrum are quantitatively exploited and experimentally verified.The theoretical and experimental results show that accompanying the increase of the interchannel phase difference,the sound image broadens as the signal frequency band width increases.When the sound image is analyzed by use of the interaural cross correlation function IACC ,the results show that with the increase of the interchannel phase difference, IACC decreases with the increase of the signal frequency band width,thus causing the decrease of definition of the sound image.However,by use of the interaural cross correlation function for analysis,the sound image“centre” position is broadened during reproduction.The paper also points out that in order to guarantee the definitive position of reproduction and the definite sound image,the interchannel phase difference should be reduced at least to less than 60°.