Skip to main content

Research Repository

Advanced Search

How ‘hidden hearing loss’ noise exposure affects neural coding in the inferior colliculus of rats

Bakay, Warren M.H.; Cervantes, Blanca; Lao-Rodríguez, Ana B.; Johannesen, Peter T.; Lopez-Poveda, Enrique A.; Furness, David N.; Malmierca, Manuel S.

Authors

Warren M.H. Bakay

Blanca Cervantes

Ana B. Lao-Rodríguez

Peter T. Johannesen

Enrique A. Lopez-Poveda

David N. Furness

Manuel S. Malmierca



Abstract

Exposure to brief, intense sound can produce profound changes in the auditory system, from the internal structure of inner hair cells to reduced synaptic connections between the auditory nerves and the inner hair cells. Moreover, noisy environments can also lead to alterations in the auditory nerve or to processing changes in the auditory midbrain, all without affecting hearing thresholds. This so-called hidden hearing loss (HHL) has been shown in tinnitus patients and has been posited to account for hearing difficulties in noisy environments. However, much of the neuronal research thus far has investigated how HHL affects the response characteristics of individual fibres in the auditory nerve, as opposed to higher stations in the auditory pathway. Human models show that the auditory nerve encodes sound stochastically. Therefore, a sufficient reduction in nerve fibres could result in lowering the sampling of the acoustic scene below the minimum rate necessary to fully encode the scene, thus reducing the efficacy of sound encoding.
Here, we examine how HHL affects the responses to frequency and intensity of neurons in the inferior colliculus of rats, and the duration and firing rate of those responses. Finally, we examined how shorter stimuli are encoded less effectively by the auditory midbrain than longer stimuli, and how this could lead to a clinical test for HHL.

Citation

Bakay, W. M., Cervantes, B., Lao-Rodríguez, A. B., Johannesen, P. T., Lopez-Poveda, E. A., Furness, D. N., & Malmierca, M. S. (2024). How ‘hidden hearing loss’ noise exposure affects neural coding in the inferior colliculus of rats. Hearing Research, 443, Article 108963. https://doi.org/10.1016/j.heares.2024.108963

Journal Article Type Article
Acceptance Date Jan 20, 2024
Online Publication Date Jan 21, 2024
Publication Date Mar 1, 2024
Deposit Date Mar 19, 2024
Journal Hearing Research
Print ISSN 0378-5955
Electronic ISSN 1878-5891
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 443
Article Number 108963
DOI https://doi.org/10.1016/j.heares.2024.108963
Keywords Hearing loss; Cochlear synaptopathy; Noise exposure; Temporary threshold shift; Inferior colliculus; Single unit electrophysiology