Enhancing sensitivity to interaural delays at high frequencies by using "transposed stimuli"
Enhancing sensitivity to interaural delays at high frequencies by using "transposed stimuli"
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DOI：
10.1121/1.1497620
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发表时间：
2002-09-01
影响因子：
2.4
通讯作者：
Trahiotis, C
中科院分区：
文献类型：
--
作者：
Bernstein, LR;Trahiotis, C
众所周知，在高频下进行的耳间时间差异（ITD）的阈值大于在低频下获得的阈值ITD。这些差异可能反映了介导性能的双耳机制的真正差异。或者，如科尔本和埃斯奎索建议的[J. Acoust.美国社会Suppl.159，S23（1976）]，它们可以反映刺激的外周加工的差异。为了研究这一问题，使用三种类型的刺激测量阈值ITD：（1）低频纯音;（2）100%正弦幅度调制（SAM）高频音，以及（3）特殊的“转置”高频刺激，其包络被设计为向高频通道提供与低频通道中可用的信息相似的信息。这些数据及其解释可以用两个一般性陈述来描述。首先，阈值ITDs获得的转置刺激一般小于SAM音调，并在128和64赫兹的调制频率，等于或小于阈值ITDs获得的低频纯音对应。第二，定量分析表明，数据可以很好地占通过一个模型的基础上归一化的耳间相关性计算后的已知阶段的周边听觉处理增强的低通滤波的包络内的高频通道的每只耳朵。定量分析的数据和结果似乎与Colbum和Esquissaud的假设的一般思想是一致的。(C)2002年美国声学学会。
It is well-known that thresholds for ongoing interaural temporal disparities (ITDs) at high frequencies are larger than threshold ITDs obtained at low frequencies. These differences could reflect true differences in the binaural mechanisms that mediate performance. Alternatively, as suggested by Colburn and Esquissaud [J. Acoust. Soc. Am. Suppl. 1 59, S23 (1976)], they could reflect differences in the peripheral processing of the stimuli. In order to investigate this issue, threshold ITDs were measured using three types of stimuli: (1) low-frequency pure tones; (2) 100% sinusoidally amplitude-modulated (SAM) high-frequency tones, and (3) special, "transposed" high-frequency stimuli whose envelopes were designed to provide the high-frequency channels with information similar to that available in low-frequency channels. The data and their interpretation can be characterized by two general statements. First, threshold ITDs obtained with the transposed stimuli were generally smaller than those obtained with SAM tones and, at modulation frequencies of 128 and 64 Hz, were equal to or smaller than threshold ITDs obtained with their low-frequency pure-tone counterparts. Second, quantitative analyses revealed that the data could be well accounted for via a model based on normalized interaural correlations computed subsequent to known stages of peripheral auditory processing augmented by low-pass filtering of the envelopes within the high-frequency channels of each ear. The data and the results of the quantitative analyses appear to be consistent with the general ideas comprising Colbum and Esquissaud's hypothesis. (C) 2002 Acoustical Society of America.