The search for noise-induced cochlear synaptopathy in humans:Mission impossible?

Bramhall, Naomi and Beach, Elizabeth and Epp, Bastian and Le Prell, Colleen and Lopez-Poveda, Enrique A. and Plack, Christopher John and Schaette, Roland and Verhulst, Sarah and Canlon, Barbara (2019) The search for noise-induced cochlear synaptopathy in humans:Mission impossible? Hearing Research, 377. pp. 88-103. ISSN 0378-5955

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Animal studies demonstrate that noise exposure can permanently damage the synapses between inner hair cells and auditory nerve fibers, even when outer hair cells are intact and there is no clinically relevant permanent threshold shift. Synaptopathy disrupts the afferent connection between the cochlea and the central auditory system and is predicted to impair speech understanding in noisy environments and potentially result in tinnitus and/or hyperacusis. While cochlear synaptopathy has been demonstrated in numerous experimental animal models, synaptopathy can only be confirmed through post-mortem temporal bone analysis, making it difficult to study in living humans. A variety of non-invasive measures have been used to determine whether noise-induced synaptopathy occurs in humans, but the results are conflicting. The overall objective of this article is to synthesize the existing data on the functional impact of noise-induced synaptopathy in the human auditory system. The first section of the article summarizes the studies that provide evidence for and against noise-induced synaptopathy in humans. The second section offers potential explanations for the differing results between studies. The final section outlines suggested methodologies for diagnosing synaptopathy in humans with the aim of improving consistency across studies.

Item Type:
Journal Article
Journal or Publication Title:
Hearing Research
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This is the author’s version of a work that was accepted for publication in Hearing Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Hearing Research, 377, 2019 DOI: 10.1016/j.heares.2019.02.016
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18 Mar 2019 11:15
Last Modified:
05 Nov 2023 01:09