The effect of interaural timing on the posterior auricular muscle reflex in normal adult volunteers

The posterior auricular muscle (PAM) reflex to sounds has been used clinically to determine hearing threshold as an alternative to other audiological diagnostic measures such as the auditory brainstem response. We have shown that the PAM response is also sensitive to interaural timing differences in normally hearing adults. PAM responses were evoked by both ipsilateral/ contralateral monaural stimulation and by binaural stimulation. Introducing sound delays ipsilaterally or contralaterally decreased the PAM response amplitude and increased its latency. The PAM response in this study shows a qualitatively similar pattern to that seen by the binaural interaction component (BIC) of the auditory brainstem potential to binaural clicks described in previous studies, in that both: have their shortest latency and maximal amplitudes centered around zero interaural timing differences, have response latencies increase with increasing interaural delays up to 1.2 ms and have response amplitudes decr...

声音诱发的耳后肌（posterior auricular muscle, PAM）反射在临床中常被用作听力阈值检测的替代方案，可替代听性脑干反应（auditory brainstem response）等各类听力学诊断手段。本研究团队证实，耳后肌反应对听力正常成年人的耳间时间差同样具备敏感性。本次研究中，通过同侧/对侧单耳刺激以及双耳刺激均可诱发出耳后肌反应。在同侧或对侧引入声音延迟，会降低耳后肌反应的幅值，并延长其反应潜伏期。本研究中的耳后肌反应，其定性模式与既往研究中描述的、听性脑干电位对双耳短声的双耳交互成分（binaural interaction component, BIC）表现出的模式相似，具体体现为二者均：最短潜伏期与最大幅值均集中于耳间时间差为0的条件下；反应潜伏期随耳间延迟增至1.2 ms的过程中不断延长；且反应幅值随……