Litovsky R Y, Rakerd B, Yin T C, Hartmann W M
Department of Neurophysiology, University of Wisconsin-Madison, 53706, USA.
J Neurophysiol. 1997 Apr;77(4):2223-6. doi: 10.1152/jn.1997.77.4.2223.
A listener in a room is exposed to multiple versions of any acoustical event, coming from many different directions in space. The precedence effect is thought to discount the reflected sounds in the computation of location, so that a listener perceives the source near its true location. According to most auditory theories, the precedence effect is mediated by binaural differences. This report presents evidence that the precedence effect operates in the median sagittal plane, where binaural differences are virtually absent and where spectral cues provide information regarding the location of sounds. Parallel studies were conducted in psychophysics by measuring human listeners' performance, and in neurophysiology by measuring responses of single neurons in the inferior colliculus of cats. In both experiments the precedence effect was found to operate similarly in the azimuthal and sagittal planes. It is concluded that precedence is mediated by binaurally based and spectrally based localization cues in the azimuthal and sagittal planes, respectively. Thus, models that attribute the precedence effect entirely to processes that involve binaural differences are no longer viable.
房间里的听众会接触到任何声学事件的多个版本，这些声音来自空间中的许多不同方向。优先效应被认为在位置计算中会忽略反射声，从而使听众在声源的真实位置附近感知到声源。根据大多数听觉理论，优先效应是由双耳差异介导的。本报告提供的证据表明，优先效应在正中矢状面起作用，在该平面中几乎不存在双耳差异，且频谱线索提供有关声音位置的信息。通过测量人类听众的表现，在心理物理学领域进行了平行研究；通过测量猫下丘中单个神经元的反应，在神经生理学领域进行了平行研究。在这两个实验中，均发现优先效应在方位平面和矢状平面中的运作方式相似。得出的结论是，优先效应在方位平面和矢状平面中分别由基于双耳和基于频谱的定位线索介导。因此，将优先效应完全归因于涉及双耳差异的过程的模型不再可行。
