Williams E A, Brookes G B, Prasher D K
Department of Neuro-otology, National Hospital for Neurology and Neurosurgery, London, UK.
Acta Otolaryngol. 1994 Mar;114(2):121-9. doi: 10.3109/00016489409126029.
The effects of contralateral acoustic stimulation on evoked otoacoustic emissions (OAE) were examined in three subject groups in order that the impact of efferent olivocochlear bundle section (as a consequence of vestibular neurectomy) could be compared with normal findings, and with a control surgical population. Results demonstrated that the inhibitory effect of contralateral noise on OAE amplitude was absent from the cochlea with severed efferent fibers. These findings appear to be independent of acoustic reflex activity, as suppression was absent despite normal reflexes. Inter-aural suppression of emissions recorded from the patients' intact cochleae act as a control and show a clear reduction in amplitude during contralateral stimulation in a frequency specific pattern consistent with normal findings. Patients who had undergone a similar surgical approach for vascular decompression of the VIIIth nerve without vestibular nerve section, were studied in order to assess the impact of retrolabyrinthine surgery on inter-aural suppression. Inhibition of OAE amplitude was maintained in all control cases in both the operated and intact sides, and was consistent with suppression observed in normal subjects, suggesting that the surgical procedures had not disturbed inter-aural suppression of otoacoustic emissions. It is concluded that the olivocochlear efferent system, when activated by low level contralateral acoustic stimulation, has an inhibitory role in controlling the cellular mechanisms responsible for the generation of otoacoustic emissions in humans. OAE techniques in conjunction with contralateral acoustic stimulation may thus prove to be of value in providing a rapid and non-invasive clinical test of efferent function and offer a means of investigating the functional significance of the efferent auditory system in humans.
在三组受试者中研究了对侧声刺激对诱发耳声发射（OAE）的影响，以便将传出橄榄耳蜗束切断（由于前庭神经切除术）的影响与正常结果以及对照手术人群进行比较。结果表明，传出纤维切断的耳蜗对侧噪声对OAE幅度的抑制作用消失。这些发现似乎与声反射活动无关，因为尽管反射正常，但抑制作用仍不存在。从患者完整耳蜗记录的耳间发射抑制作为对照，并且在对侧刺激期间幅度明显降低，呈现出与正常结果一致的频率特异性模式。对那些接受了类似手术方法进行第八脑神经血管减压但未进行前庭神经切断的患者进行了研究，以评估迷路后手术对耳间抑制的影响。在所有对照病例中，手术侧和完整侧的OAE幅度抑制均得以维持，并且与正常受试者中观察到的抑制一致，这表明手术操作并未干扰耳声发射的耳间抑制。得出的结论是，当由低水平对侧声刺激激活时，橄榄耳蜗传出系统在控制负责人类耳声发射产生的细胞机制方面具有抑制作用。因此，OAE技术与对侧声刺激相结合可能被证明在提供传出功能的快速、非侵入性临床测试以及提供一种研究人类传出听觉系统功能意义的手段方面具有价值。
