Stellmack Mark A, Viemeister Neal F, Byrne Andrew J
Department of Psychology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
J Acoust Soc Am. 2005 Jul;118(1):346-52. doi: 10.1121/1.1923370.
Psychometric functions were measured for the discrimination of the interaural phase difference (IPD) of the envelope of a sinusoidally amplitude-modulated (SAM) 4-kHz pure tone for modulation frequencies of 128 and 300 Hz and modulation depths (m) of 0.2, 0.6, 0.9, and 1.0. Contrary to recent modeling assumptions, it was found that a constant change in normalized interaural envelope correlation, with or without additional model stages to simulate peripheral auditory processing, did not produce a constant level of performance. Rather, in some cases, performance could range from chance to near perfect across modulation depths for a given change in normalized interaural envelope correlation. This was also true for the maximum change in normalized interaural envelope correlation computed across the cross-correlation functions for the stimuli to be discriminated. The change in the interaural time difference (ITD) computed from the IPD accounted for discriminability across modulation depths better than the change in normalized interaural envelope correlation, although ITD could not account for all the data, particularly those for lower values of m.
测量了心理测量函数，用于辨别频率为128Hz和300Hz、调制深度（m）分别为0.2、0.6、0.9和1.0的正弦幅度调制（SAM）4kHz纯音包络的耳间相位差（IPD）。与最近的建模假设相反，研究发现，无论是否有额外的模型阶段来模拟外周听觉处理，归一化耳间包络相关性的恒定变化都不会产生恒定水平的性能。相反，在某些情况下，对于归一化耳间包络相关性的给定变化，性能在不同调制深度下可能从随机到接近完美。对于要辨别的刺激，在互相关函数中计算出的归一化耳间包络相关性的最大变化也是如此。从IPD计算出的耳间时间差（ITD）的变化比归一化耳间包络相关性的变化更能解释不同调制深度下的可辨别性，尽管ITD不能解释所有数据，特别是m值较低的数据。
