University of Massachusetts, Communication Disorders, Amherst, Massachusetts 01003, USA.
J Acoust Soc Am. 2010 Jul;128(1):320-31. doi: 10.1121/1.3436560.
The lateralization of 250-ms trains of brief noise bursts was measured using an acoustic pointing technique. Stimuli were designed to assess the contribution of the interaural time delay (ITD) of the onset binaural burst relative to that of the ITDs in the ongoing part of the train. Lateralization was measured by listeners' adjustments of the ITD of a pointer stimulus, a 50-ms burst of noise, to match the lateral position of the target train. Results confirmed previous reports of lateralization dominance by the onset burst under conditions in which the train is composed of frozen tokens and the ongoing part contains multiple ambiguous interaural delays. In contrast, lateralization of ongoing trains in which fresh noise tokens were used for each set of two alternating (left-leading/right-leading) binaural pairs followed the ITD of the first pair in each set, regardless of the ITD of the onset burst of the entire stimulus and even when the onset burst was removed by gradual gating. This clear lateralization of a long-duration stimulus with ambiguous interaural delay cues suggests precedence mechanisms that involve not only the interaural cues at the beginning of a sound, but also the pattern of cues within an ongoing sound.
使用声指向技术测量了 250 毫秒短噪声突发串的侧化。刺激设计用于评估起始双耳突发的耳间时间延迟 (ITD) 相对于突发串中持续部分的 ITD 的贡献。通过听众调整指针刺激的 ITD 来测量侧化，指针刺激是一个 50 毫秒的噪声突发。结果证实了先前的报告，即在冻结令牌组成的突发串中，以及持续部分包含多个模糊的耳间延迟的情况下，起始突发具有侧化优势。相比之下，在使用每个双声道对的新噪声令牌的情况下，每个双声道对的交替（左领先/右领先）的持续列车的侧化遵循每个对的第一对的 ITD，而不考虑整个刺激的起始突发的 ITD，即使起始突发被逐渐门控去除。这种具有模糊耳间延迟线索的长持续时间刺激的明显侧化表明，优先机制不仅涉及声音开始时的耳间线索，还涉及持续声音中的线索模式。
