Stapes displacement and intracochlear pressure in response to very high level, low frequency sounds.

Stapes displacement and intracochlear pressure in response to very high level, low frequency sounds.
Hear Res. 2017 Feb 08;:
Authors: Greene NT, Jenkins HA, Tollin DJ, Easter JR
Abstract
The stapes is held in the oval window by the stapedial annular ligament (SAL), which restricts total peak-to-peak displacement of the stapes. Previous studies have suggested that for moderate (<130 dB SPL) sound levels intracochlear pressure (PIC), measured at the base of the cochlea far from the basilar membrane, increases directly proportionally with stapes displacement (DStap), thus a current model of impulse noise exposure (the Auditory Hazard Assessment Algorithm for Humans, or AHAAH) predicts that peak PIC will vary linearly with DStap up to some saturation point. However, no direct tests of DStap, or of the relationship with PIC during such motion, have been performed during acoustic stimulation of the human ear. In order to examine the relationship between DStap and PIC to very high level sounds, measurements of DStap and PIC were made in cadaveric human temporal bones. Specimens were prepared by mastoidectomy and extended facial recess to expose the ossicular chain. Measurements of PIC were made in scala vestibuli (PSV) and scala tympani (PST), along with the SPL in the external auditory canal (PEAC), concurrently with laser Doppler vibrometry (LDV) measurements of stapes velocity (VStap). Stimuli were moderate (∼100 dB SPL) to very h...

Source: Hearing Research - February 7, 2017 Category: Audiology Authors: Greene NT, Jenkins HA, Tollin DJ, Easter JR Tags: Hear Res Source Type: research