Related Experiment Video
Updated: Jun 9, 2026

Testing Tactile Masking between the Forearms
Published on: February 10, 2016
Efferent-induced change in human cochlear compression and its influence on masking of tones
Shaum P Bhagat1, Paul H Carter
1Hearing Science Laboratory, School of Audiology and Speech-Language Pathology, The University of Memphis, 807 Jefferson Avenue, Memphis, TN 38105, United States. sbhagat@memphis.edu
Abstract:
Several lines of evidence suggest that medial olivocochlear (MOC) efferent neurons modify cochlear output to improve signal detection in noise. In animal models, stimulation of MOC efferents reduces the amount of compression in basilar membrane (BM) growth functions. Linearization of BM growth functions may assist in extending the neural response to the signal above that of noise, leading to a decrease in masking. In order to test this hypothesis, effects of MOC efferent neurons on BM compression were studied indirectly in humans by examining the effects of contralateral noise on distortion-product otoacoustic emission (DPOAE) input-output functions at 1.0 and 2.0kHz. Compression threshold estimates from a three-segment linear regression model applied to the DPOAE functions were derived in order to determine correlations with psychophysical measurements of masking of tones at 1.0 and 2.0kHz. Contralateral noise shifted the DPOAE compression threshold to a significantly higher level at 1.0kHz, but not at 2.0kHz. A significant negative correlation between the change in DPOAE compression threshold and the amount of masking at 1.0kHz was observed, but no correlation between these variables was detected at 2.0kHz. The results of this experiment at the lower test frequency indicated that contralateral noise linearized DPOAE input-output functions, and individuals with larger DPOAE compression threshold shifts tended to exhibit less masking. Under certain conditions, decreases in cochlear compression induced by MOC efferent neurons may lead to unmasking of tones presented in noise.
More Related Videos
09:06Cochlear Implant Surgery and Electrically-evoked Auditory Brainstem Response Recordings in C57BL/6 Mice
Published on: January 9, 2019
10:50Behavioral Determination of Stimulus Pair Discrimination of Auditory Acoustic and Electrical Stimuli Using a Classical Conditioning and Heart-rate Approach
Published on: June 6, 2012
Related Concept Videos
The Cochlea
Hearing
Hair Cells
Auditory Pathway
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...