Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, 2240 Campus Drive, Evanston, IL 60208, USA.
J Assoc Res Otolaryngol. 2010 Mar;11(1):53-67. doi: 10.1007/s10162-009-0189-4. Epub 2009 Oct 2.
Evoked otoacoustic emissions are often used to study the medial olivocochlear (MOC) efferents in humans. There has been concern that the emission-evoking stimulus may itself elicit efferent activity and alter the evoked otoacoustic emission. Spontaneous otoacoustic emissions (SOAEs) are hence advantageous as no external stimulation is necessary to record the response in the test ear. Contralateral acoustic stimulation (CAS) has been shown to suppress SOAE level and elevate SOAE frequency, but the time course of these effects is largely unknown. By utilizing the Choi-Williams distribution, here we report a gradual adaptation during the presence of CAS and an overshoot following CAS offset in both SOAE magnitude and frequency from six normal-hearing female human subjects. Furthermore, we have quantified the time constants of both magnitude and frequency shifts at the onset, presence, and offset of four levels of CAS. Most studies using contralateral elicitors do not stringently control the middle-ear muscle (MEM) reflex, leaving the results difficult to interpret. In addition to clinically available measures of the MEM reflex, we have incorporated a sensitive laboratory technique to monitor the MEM reflex in our subjects, allowing us to interpret the results with greater confidence.
诱发耳声发射常用于研究人类的内侧橄榄耳蜗（MOC）传出。人们一直担心，发射激发刺激本身可能会引发传出活动并改变诱发耳声发射。因此，自发性耳声发射（SOAEs）具有优势，因为不需要外部刺激即可记录测试耳的反应。已经证明，对侧声刺激（CAS）会抑制 SOAE 水平并提高 SOAE 频率，但这些效应的时间过程在很大程度上尚不清楚。通过利用 Choi-Williams 分布，我们在这里报告了在 CAS 存在期间的逐渐适应，以及在 CAS 消除后，来自六位正常听力女性人类受试者的 SOAE 幅度和频率都出现过冲。此外，我们已经量化了在四个级别的 CAS 的起始、存在和消除时幅度和频率偏移的时间常数。大多数使用对侧激发器的研究都没有严格控制中耳肌（MEM）反射，使得结果难以解释。除了可用于临床的 MEM 反射测量外，我们还采用了一种灵敏的实验室技术来监测我们受试者的 MEM 反射，从而使我们更有信心地解释结果。
