Acoustic Reflex
An involuntary contraction of the stapedius muscle (and tensor tympani) in response to loud sounds, measurable by immittance audiometry as an objective indicator of middle ear and auditory nerve function.
Full Definition
The acoustic reflex (also called the stapedial reflex or stapedius reflex) is mediated by a neural arc involving the cochlear nerve, cochlear nucleus, superior olivary complex, facial nerve nucleus, and stapedius muscle. It is tested during immittance audiometry by presenting a high-intensity tone and measuring the resulting change in middle ear admittance. The acoustic reflex threshold (ART) and the presence or absence of decay are clinically important for differentiating cochlear from retrocochlear pathology. Editors should note that 'acoustic reflex' and 'acoustic reflex threshold' are not synonymous and should not be used interchangeably.
Usage
Usage note: Specify whether the reflex tested is ipsilateral or contralateral, and always indicate the stimulus frequency and level when reporting acoustic reflex data.
In Context
- "Absent acoustic reflexes ipsilaterally and contralaterally at all frequencies raised suspicion for retrocochlear pathology." — Diagnostic audiology report
- "Ensure 'acoustic reflex' and 'acoustic reflex threshold' are used precisely and not conflated in the results section." — Journal manuscript editing