The proposed program of research will increase our knowledge of cochlear function through a combination of theoretical and empirical studies addressing fundamental processes in ways that have both basic and translational implications. The program focuses on two interrelated areas: (1) the level-dependence of cochlear delays and (2) the effect on cochlear response growth at a particular frequency due to the presence of suppressors at other frequencies. Suppression and level-dependent latency share a common mechanism that is primarily responsible for cochlear compression. These areas represent features of normal cochlear function that are affected by cochlear hearing loss and potentially may be remediated by external hearing aids that incorporate sophisticated signal-processing strategies. The first two Aims of the proposal are to further understand (1) cochlear-reflectance generation and (2) the latency and masking of cochlear transients. Cochlear reflectance is defined as a transfer function between pressure waves entering and exiting the cochlea, and has advantages over other measures of cochlear responses. The remaining Aims are to determine the influence of (3) high-frequency suppression on cochlear distortion generators and (4) low- frequency suppression on cochlear compression. Through the work related to these four Aims, questions that possess both basic scientific interest and applied clinical relevance wil be answered by combined application of measurement and modeling efforts.

Public Health Relevance

The proposed research program will obtain measurements in human subjects and develop simulations with mathematical models related to (1) the travel time of transient sounds through the inner ear and (2) the interaction among frequency components of complex sounds. Comparisons between these measurements and simulations will address basic scientific questions and also will have clinical relevance in their potential to improve intervention strategies for hearing loss.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Research Project (R01)
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Auditory System Study Section (AUD)
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Donahue, Amy
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Father Flanagan's Boys' Home
Boys Town
United States
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Ridley, Courtney L; Kopun, Judy G; Neely, Stephen T et al. (2018) Using Thresholds in Noise to Identify Hidden Hearing Loss in Humans. Ear Hear 39:829-844
Siegel, Jonathan H; Nørgaard, Kren Rahbek; Neely, Stephen T (2018) Evanescent waves in simulated ear canals: Experimental demonstration and method for compensation. J Acoust Soc Am 144:2135
Nørgaard, Kren Rahbek; Neely, Stephen T; Rasetshwane, Daniel M (2018) Quantifying undesired parallel components in Thévenin-equivalent acoustic source parameters. J Acoust Soc Am 143:1491
Neely, Stephen T; Fultz, Sara E; Kopun, Judy G et al. (2018) Cochlear Reflectance and Otoacoustic Emission Predictions of Hearing Loss. Ear Hear :
Trevino, Andrea C; Jesteadt, Walt; Neely, Stephen T (2016) Development of a multi-category psychometric function to model categorical loudness measurements. J Acoust Soc Am 140:2571
Sieck, Nicole E; Rasetshwane, Daniel M; Kopun, Judy G et al. (2016) Multi-tone suppression of distortion-product otoacoustic emissions in humans. J Acoust Soc Am 139:2299
Trevino, Andrea C; Jesteadt, Walt; Neely, Stephen T (2016) Modeling the Individual Variability of Loudness Perception with a Multi-Category Psychometric Function. Adv Exp Med Biol 894:155-164
Rasetshwane, Daniel M; Fultz, Sara E; Kopun, Judy G et al. (2015) Reliability and clinical test performance of cochlear reflectance. Ear Hear 36:111-24
Rasetshwane, Daniel M; Neely, Stephen T (2015) Reflectance measurement validation using acoustic horns. J Acoust Soc Am 138:2246-55
Lewis, James D; Kopun, Judy; Neely, Stephen T et al. (2015) Tone-burst auditory brainstem response wave V latencies in normal-hearing and hearing-impaired ears. J Acoust Soc Am 138:3210-9

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