Department of Psychology, University of Minnesota, 75 East River Road, Minneapolis, Minnesota 55455, USA.
J Acoust Soc Am. 2012 Jan;131(1):363-77. doi: 10.1121/1.3665995.
Cochlear filtering results in earlier responses to high than to low frequencies. This study examined potential perceptual correlates of cochlear delays by measuring the perception of relative timing between tones of different frequencies. A brief 250-Hz tone was combined with a brief 1-, 2-, 4-, or 6-kHz tone. Two experiments were performed, one involving subjective judgments of perceived synchrony, the other involving asynchrony detection and discrimination. The functions relating the proportion of "synchronous" responses to the delay between the tones were similar for all tone pairs. Perceived synchrony was maximal when the tones in a pair were gated synchronously. The perceived-synchrony function slopes were asymmetric, being steeper on the low-frequency-leading side. In the second experiment, asynchrony-detection thresholds were lower for low-frequency rather than for high-frequency leading pairs. In contrast with previous studies, but consistent with the first experiment, thresholds did not depend on frequency separation between the tones, perhaps because of the elimination of within-channel cues. The results of the two experiments were related quantitatively using a decision-theoretic model, and were found to be highly correlated. Overall the results suggest that frequency-dependent cochlear group delays are compensated for at higher processing stages, resulting in veridical perception of timing relationships across frequency.
耳蜗滤波导致对高频的响应早于低频。本研究通过测量不同频率的音之间相对定时的感知来检查耳蜗延迟的潜在感知相关性。一个简短的 250Hz 音与一个简短的 1、2、4 或 6kHz 音组合。进行了两项实验，一项涉及对感知同步性的主观判断，另一项涉及异步检测和辨别。所有音对的比例与音之间的延迟之间的关系函数都相似。当一对音同步门控时，感知同步性达到最大值。感知同步函数的斜率不对称，在低频领先侧更陡峭。在第二个实验中，低频领先对的异步检测阈值低于高频领先对。与以前的研究相反，但与第一个实验一致，阈值不取决于音之间的频率分离，可能是因为消除了通道内线索。使用决策理论模型对两个实验的结果进行了定量相关，发现它们高度相关。总的来说，这些结果表明，频率相关的耳蜗群延迟在较高的处理阶段得到补偿，从而在跨频率的时间关系感知中得到真实的感知。
