The overall theme of this research program is to describe cochlear nonlinearities in humans with normal hearing and with hearing loss. Cochlear nonlinearities are evident in many measures, all of which change as a consequence of damage to the peripheral auditory system. It is not possible to directly assess cochlear status in humans, but indirect acoustical and electrophysiological measures can be used to assess nonlinear behavior in responses that describe cochlear function. It also is possible to test the hypothesis that different measures reflect the influences from common underlying mechanisms. Studies included in this proposal will (1) increase our knowledge of underlying processes responsible for the relationship between sensitivity loss and otoacoustic emission generation, (2) lead to a better understanding of the consequences of damage to nonlinear mechanisms with respect to response latencies, (3) describe the changes in suprathreshold function following cochlear damage, and (4) lead to better diagnostic tests that identify the sensory cell population underlying hearing loss in humans. It is hypothesized that all of the phenomena to be studied as part of this research program may reflect different manifestations of a single underlying mechanism associated with cochlear nonlinearities. This unified interpretation will be evaluated with multiple correlational analyses and by manipulation of a simple cochlear model that has anatomical correlates. The melding of both basic and clinical studies will lead to advancements in knowledge of auditory function in humans with normal hearing and with hearing loss, leading to improvements in how hearing loss is identified, quantified and remediated. These improvements, being based on objective measures of threshold and suprathreshold function, will be especially helpful in the diagnosis and treatment of hearing loss in infants, young children, and patients with developmental delay.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Research Project (R01)
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Special Emphasis Panel (ZRG1-IFCN-6 (01))
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Donahue, Amy
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Father Flanagan's Boys' Home
Boys Town
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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
McCreery, Ryan W; Kaminski, Jan; Beauchaine, Kathryn et al. (2015) The impact of degree of hearing loss on auditory brainstem response predictions of behavioral thresholds. Ear Hear 36:309-19
Rasetshwane, Daniel M; Trevino, Andrea C; Gombert, Jessa N et al. (2015) Categorical loudness scaling and equal-loudness contours in listeners with normal hearing and hearing loss. J Acoust Soc Am 137:1899-913
Rasetshwane, Daniel M; Gorga, Michael P; Neely, Stephen T (2014) Signal-processing strategy for restoration of cross-channel suppression in hearing-impaired listeners. IEEE Trans Biomed Eng 61:64-75
Rasetshwane, Daniel M; Neely, Stephen T; Kopun, Judy G et al. (2013) Relation of distortion-product otoacoustic emission input-output functions to loudness. J Acoust Soc Am 134:369-83
Rasetshwane, Daniel M; Argenyi, Michael; Neely, Stephen T et al. (2013) Latency of tone-burst-evoked auditory brain stem responses and otoacoustic emissions: level, frequency, and rise-time effects. J Acoust Soc Am 133:2803-17
Reuven, Michal L; Neely, Stephen T; Kopun, Judy G et al. (2013) Effect of calibration method on distortion-product otoacoustic emission measurements at and around 4 kHz. Ear Hear 34:779-88
Birkholz, Cori; Gruhlke, Alyson; Neely, Stephen T et al. (2012) Growth of suppression using distortion-product otoacoustic emission measurements in hearing-impaired humans. J Acoust Soc Am 132:3305-18
Thorson, Megan J; Kopun, Judy G; Neely, Stephen T et al. (2012) Reliability of distortion-product otoacoustic emissions and their relation to loudness. J Acoust Soc Am 131:1282-95
Gruhlke, Alyson; Birkholz, Cori; Neely, Stephen T et al. (2012) Distortion-product otoacoustic emission suppression tuning curves in hearing-impaired humans. J Acoust Soc Am 132:3292-304

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