van Hoesel Richard J M
The Hearing CRC, East Melbourne, Victoria 3002, Australia.
J Acoust Soc Am. 2008 Dec;124(6):3861-72. doi: 10.1121/1.2998974.
The contribution of binaural level and timing cues available from each pulse in brief electrical pulse trains was determined in a lateralization task using an observer weighting paradigm. Four bilateral cochlear implant users were tested with randomized interaural time delays (ITDs) or, in a separate experimental condition, interaural level differences (ILDs) applied to each pulse at 100, 300, and 600 pulsess. To examine the effect of cue randomization, weights were also determined for stimuli with a common ITD applied to all postonset pulses. Listeners were further tested for the ability to restart binaural ITD sensitivity at a rate that produced onset dominance by reducing a single interpulse interval in the stimulus. Results showed that the onset always exerted a strong influence. At 100 pulsess, postonset ITDs and ILDs also contributed strongly. At 300 and 600 pulsess, contributions from postonset pulses remained substantial for ILDs but were much reduced for ITDs, particularly at 600 pulsess. Weights were similar with either independent or common ITD cues applied to postonset pulses, indicating that the cue randomization process itself did not affect weights. Restarting of ITD sensitivity at 300 pulsess by introducing a single reduced interpulse interval was not observed.
在一项使用观察者加权范式的定位任务中，确定了短暂电脉冲序列中每个脉冲的双耳声级和时间线索的作用。对四名双侧人工耳蜗使用者进行了测试，采用随机耳间时间延迟（ITD），或者在另一个实验条件下，对100、300和600个脉冲的每个脉冲施加耳间声级差（ILD）。为了检验线索随机化的效果，还确定了对所有起始后脉冲施加相同ITD的刺激的权重。通过减少刺激中的单个脉冲间隔，以产生起始优势的速率进一步测试了听众重新启动双耳ITD敏感性的能力。结果表明，起始总是产生强烈影响。在100个脉冲时，起始后ITD和ILD也有很大贡献。在300和600个脉冲时，起始后脉冲对ILD的贡献仍然很大，但对ITD的贡献大大减少，尤其是在600个脉冲时。对起始后脉冲应用独立或相同ITD线索时权重相似，表明线索随机化过程本身不影响权重。未观察到通过引入单个减少的脉冲间隔在300个脉冲时重新启动ITD敏感性。
