Department of Speech and Hearing Science, University of Illinois at Urbana-Champaign, 901 South Sixth Street, Champaign, IL, 61820, United States.
Hear Res. 2018 Aug;365:100-109. doi: 10.1016/j.heares.2018.05.007. Epub 2018 May 16.
The medial olivocochlear reflex (MOCR) modifies cochlear amplifier function to improve encoding of signals in static noise, but conflicting results have been reported regarding how the MOCR responds to dynamic, temporally-complex noises. The current study utilized three MOCR elicitors with identical spectral content but different temporal properties: broadband noise, amplitude-modulated noise, and speech envelope-modulated noise. MOCR activity was assessed using contralateral inhibition of transient-evoked otoacoustic emissions in 27 normal-hearing young adults. Elicitors were presented contralaterally at two intensities of 50 and 60 dB SPL. Magnitude and growth of contralateral inhibition with increasing elicitor intensity were compared across the three elicitor types. Results revealed that contralateral inhibition was significantly larger at the elicitor intensity of 60 dB SPL than at 50 dB SPL, but there were no significant differences in the magnitude and growth of inhibition across the three elicitors, contrary to hypothesis. These results suggest that the MOCR responds similarly to both static and dynamic noise.
中橄榄耳蜗反射（MOCR）调节耳蜗放大器功能，以改善静态噪声中的信号编码，但关于 MOCR 如何响应动态、时变复杂噪声，已有相互矛盾的结果报道。本研究使用三种具有相同频谱内容但时变特性不同的 MOCR 激发器：宽带噪声、调幅噪声和语音包络调制噪声。通过对 27 名听力正常的年轻成年人的瞬态诱发耳声发射的对侧抑制，评估 MOCR 活性。在 50 和 60 dB SPL 两个强度下，从对侧呈现激发器。比较三种激发器类型的激发器强度增加时的对侧抑制的幅度和增长。结果表明，在 60 dB SPL 的激发器强度下，对侧抑制明显大于 50 dB SPL，但在三种激发器中，抑制的幅度和增长没有显著差异，这与假设相反。这些结果表明，MOCR 对静态噪声和动态噪声的反应相似。
