TY - GEN
T1 - Quantifying cochlear amplifier gain using a model-based evaluation of DPOAE I/O functions in mammals
AU - Withnell, Robert H.
AU - Ohlemiller, Kevin K.
N1 - Publisher Copyright:
© 2018 Author(s).
PY - 2018/5/31
Y1 - 2018/5/31
N2 - Cochlear amplifier gain in humans and mice was quantified using a phenomenological model of DPOAE generation. The model consisted of a positive feedback loop to represent the cochlear mechanical amplifier; cochlear nonlinearity was represented by a first or second order Boltzmann function (order of the function was species-dependent). Cochlear nonlinearity was separated from the feedback loop based on the respective stimulus-level dependent dominances of the feedback loop and nonlinearity at low and high stimulus levels. The feedback parameter, Γ, was defined by a up to a five term exponential and a nonlinear least-squares fit of this equation to DPOAE data-derived values of Γ generated a stimulus-level dependent equation for Γ. DPOAE I/O functions were obtained over a range of stimulus levels and frequencies. The feedback gain, Γ, at 0 dB SPL, was used as an estimate of the cochlear amplifier feedback gain. Results showed gain to be frequency-independent, with absolute gain higher in mice than in humans for cochlear place-equivalent frequencies.
AB - Cochlear amplifier gain in humans and mice was quantified using a phenomenological model of DPOAE generation. The model consisted of a positive feedback loop to represent the cochlear mechanical amplifier; cochlear nonlinearity was represented by a first or second order Boltzmann function (order of the function was species-dependent). Cochlear nonlinearity was separated from the feedback loop based on the respective stimulus-level dependent dominances of the feedback loop and nonlinearity at low and high stimulus levels. The feedback parameter, Γ, was defined by a up to a five term exponential and a nonlinear least-squares fit of this equation to DPOAE data-derived values of Γ generated a stimulus-level dependent equation for Γ. DPOAE I/O functions were obtained over a range of stimulus levels and frequencies. The feedback gain, Γ, at 0 dB SPL, was used as an estimate of the cochlear amplifier feedback gain. Results showed gain to be frequency-independent, with absolute gain higher in mice than in humans for cochlear place-equivalent frequencies.
UR - http://www.scopus.com/inward/record.url?scp=85048228000&partnerID=8YFLogxK
U2 - 10.1063/1.5038493
DO - 10.1063/1.5038493
M3 - Conference contribution
AN - SCOPUS:85048228000
T3 - AIP Conference Proceedings
BT - To the Ear and Back Again - Advances in Auditory Biophysics
A2 - Bergevin, Christopher
A2 - Puria, Sunil
PB - American Institute of Physics Inc.
T2 - 13th Mechanics of Hearing Workshop: To the Ear and Back Again - Advances in Auditory Biophysics, MoH 2017
Y2 - 19 June 2017 through 24 June 2017
ER -