Vestibular suppression of normal bodily sounds

Abstract

Background: Vestibular-evoked myogenic potentials (VEMPs) are present in almost everyone. The proximity of the cochlear and vestibular end organs strongly indicates an overlap of the stimuli to which they respond.

Aims/objectives: To determine the loudness of shouting compared to the external auditory canal (EAC) and explore how hyperstimulation of the cochlea and vestibular structures might be prevented.

Materials and methods: We compared the loudness and frequency response of sound during shouting, biting and chewing, as well as the measurement of the loudness and frequency of sound in the external auditory canal (EAC) when a calibrated minishaker is applied to the forehead and to the upper incisor teeth.

Results: We showed that vibratory sounds produced by vocalizations and oral activities were attenuated when they reached the ear, so that these sounds would not act as vestibular stimulants.

Conclusions and significance: Chewing is known to cause a stapedius reflex which suppresses internal sounds to optimize audition of external sounds, while at the same time suppressing vestibular stimulation, which serves to optimize the sensitivity of the vestibular system, in order that it may respond precisely to a threat.

Chinese abstract

背景：前庭诱发肌源性电位（VEMPs）几乎存在于所有人。耳蜗和前庭末梢器官的靠近可以高度说明它们所响应的刺激的重叠。

目的：测定与外耳道（EAC）相比的喊叫响度, 探讨如何防止耳蜗和前庭结构的过度刺激。

材料与方法：采用听力学设备和微型发声器, 分别测量叫声、撕咬声和咀嚼声, 还测量微型发声器放置在顶面和牙齿上所产生的外耳道内的声音。

结果：喊叫声具有大于110 dB SPL的声音强度。咬合产生超过80 dB的声音振幅。一个微型震动器导致EAC中的音幅大幅度降低。

结论及意义：振动OVEMP是不可靠的。声音产生的OVEMP是一种更加一致和可靠的技术。众所周知, 发声、撕咬和咀嚼都会引起镫骨反射, 抑制内部声音以优化外部声音的听觉, 同时抑制前庭刺激。我们假设耳蜗和前庭传出通路也有类似的作用, 这进一步优化了听觉和前庭系统的敏感性。

Keywords:

• Otoliths
• vibration
• sound suppression
• VEMP
• cochlear efferents
• vestibular suppression
• vestibular efferents

Disclosure statement

No potential conflict of interest was reported by the author(s).