1 Hearing Systems Group, Department of Electrical Engineering, 307918 Technical University of Denmark , Denmark.
Trends Hear. 2018 Jan-Dec;22:2331216517750262. doi: 10.1177/2331216517750262.
Sequential stream segregation by cochlear implant (CI) listeners was investigated using a temporal delay detection task composed of a sequence of regularly presented bursts of pulses on a single electrode (B) interleaved with an irregular sequence (A) presented on a different electrode. In half of the trials, a delay was added to the last burst of the regular B sequence, and the listeners were asked to detect this delay. As a jitter was added to the period between consecutive A bursts, time judgments between the A and B sequences provided an unreliable cue to perform the task. Thus, the segregation of the A and B sequences should improve performance. In Experiment 1, the electrode separation and the sequence duration were varied to clarify whether place cues help CI listeners to voluntarily segregate sounds and whether a two-stream percept needs time to build up. Results suggested that place cues can facilitate the segregation of sequential sounds if enough time is provided to build up a two-stream percept. In Experiment 2, the duration of the sequence was fixed, and only the electrode separation was varied to estimate the fission boundary. Most listeners were able to segregate the sounds for separations of three or more electrodes, and some listeners could segregate sounds coming from adjacent electrodes.
研究者采用包含单个电极上规则呈现的脉冲串（B 序列）和另一个电极上不规则呈现的脉冲串（A 序列）的时移检测任务，对人工耳蜗（CI）使用者的连续流分离进行了研究。在一半的试验中，在规则 B 序列的最后一个脉冲串上添加了时移，要求听众检测该时移。由于在连续 A 脉冲串之间的周期内添加了抖动，因此 A 和 B 序列之间的时间判断不能可靠地提示完成任务。因此，A 和 B 序列的分离应该会提高性能。在实验 1 中，改变电极间隔和序列持续时间，以明确位置线索是否有助于 CI 使用者自愿分离声音，以及是否需要时间来建立双声道感知。结果表明，如果有足够的时间来建立双声道感知，位置线索可以促进连续声音的分离。在实验 2 中，固定序列的持续时间，仅改变电极间隔，以估计分裂边界。大多数听众能够对三个或更多电极的分离进行声音分离，一些听众可以对来自相邻电极的声音进行分离。
