Department of Speech and Hearing Sciences, University of Washington, 1417 Northeast 42nd Street, Seattle, Washington 98105, USA.
J Acoust Soc Am. 2012 Sep;132(3):1573-80. doi: 10.1121/1.4740496.
The relative sensitivity of human listeners to interaural level differences (ILDs) carried by the onsets, offsets, and interior portions of brief sounds was examined. Stimuli consisted of single 4000-Hz Gabor clicks (Gaussian-windowed tone bursts) or trains of 16 such clicks repeating at an interclick interval (ICI) of 2 or 5 ms. In separate conditions, ILDs favored the right ear by a constant amount for all clicks (condition RRRR) or a changing amount that was maximal at sound onset (condition R000), offset (condition 000R), both onset and offset (condition R00R), or at the temporal midpoint of the stimulus (condition 0RR0). ILD increases and decreases were implemented as linear decibel sweeps across four clicks to minimize transient distortion. Threshold ILDs were determined adaptively for each of these conditions and for single clicks. Thresholds were similar for ILDs presented near sound onset or offset (condition R000 vs 000R) but lower when ILDs were carried by both onset and offset clicks (condition R00R) than for ILDs carried by interior clicks alone (condition 0RR0). The results suggest that similar sensitivity to onset and offset ILD does not reflect uniform temporal weighting; instead, ILD sensitivity favors onsets and offsets over the interior portions of sounds.
研究了人类听众对短暂声音起始、结束和内部部分的耳间水平差异 (ILDs) 的相对敏感性。刺激物由单个 4000Hz 的 Gabor 点击（高斯窗调谐脉冲）或重复的 16 个此类点击组成，重复的间隔为 2 或 5 毫秒。在单独的条件下，对于所有点击，ILD 以恒定的量有利于右耳（RRRR 条件）或在声音起始时最大的变化量（R000 条件）、结束时（000R 条件）、起始和结束时（R00R 条件）或刺激的时间中点（0RR0 条件）。ILD 增加和减少通过在四个点击上进行线性分贝扫描来实现，以最小化瞬态失真。对于这些条件中的每一个以及单个点击，都自适应地确定了阈值 ILD。在声音起始或结束附近呈现的 ILD（R000 与 000R 条件）的阈值相似，但当 ILD 由起始和结束点击共同携带时（R00R 条件），比由内部点击单独携带时（0RR0 条件）的阈值低。结果表明，对起始和结束 ILD 的相似敏感性并不反映均匀的时间加权；相反，ILD 敏感性有利于起始和结束部分超过声音的内部部分。
