TY - GEN
T1 - Effects of geometry and cochlear loads on tectorial membrane traveling waves
AU - Sellon, Jonathan B.
AU - Ghaffari, Roozbeh
AU - Freeman, Dennis M.
N1 - Funding Information:
We thank John J. Guinan Jr. and Christopher A. Shera for their helpful comments and suggestions on this work. This work was supported by National Institutes of Health (NIH) grant No. R01-DC00238, and J.B.S. was supported by the National Science Foundation Graduate Research Fellowship Program (NSF GRFP) under grant No. 1122374.
PY - 2018/5/31
Y1 - 2018/5/31
N2 - It has been suggested that the decay constants of tectorial membrane (TM) traveling waves contribute to differences in the tuning of Tectb -/- mutant mice, wild-Type mice, and humans. However, the experiments underlying these results were obtained in vitro, in the absence of cochlear loads. In this work, we analyze effects of cochlear loads on TM traveling waves using a viscoelastic model. Results demonstrate that hair bundle stiffness has little effect on TM waves, the limbal attachment tends to increase the wavelength of TM waves, and viscous loss to subtectorial fluid tends to decrease the wave decay constant. To understand how the TM is able to support traveling waves despite these loads we examined how TM wave decay constants depend on thickness of the TM. We observe that increasing TM thickness tends to moderate all effects of cochlear loads and that as TM thickness increases, the wave decay constant approaches an asymptotic limit that is independent of cochlear loads. For material properties corresponding to both the apical and basal turns of the mouse TM, the asymptotic limit in decay constant is achieved at roughly the physiological thickness-suggesting an evolutionary pressure for the TM to be just thick enough to allow for wave propagation in the presence of subtectorial fluid.
AB - It has been suggested that the decay constants of tectorial membrane (TM) traveling waves contribute to differences in the tuning of Tectb -/- mutant mice, wild-Type mice, and humans. However, the experiments underlying these results were obtained in vitro, in the absence of cochlear loads. In this work, we analyze effects of cochlear loads on TM traveling waves using a viscoelastic model. Results demonstrate that hair bundle stiffness has little effect on TM waves, the limbal attachment tends to increase the wavelength of TM waves, and viscous loss to subtectorial fluid tends to decrease the wave decay constant. To understand how the TM is able to support traveling waves despite these loads we examined how TM wave decay constants depend on thickness of the TM. We observe that increasing TM thickness tends to moderate all effects of cochlear loads and that as TM thickness increases, the wave decay constant approaches an asymptotic limit that is independent of cochlear loads. For material properties corresponding to both the apical and basal turns of the mouse TM, the asymptotic limit in decay constant is achieved at roughly the physiological thickness-suggesting an evolutionary pressure for the TM to be just thick enough to allow for wave propagation in the presence of subtectorial fluid.
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U2 - 10.1063/1.5038466
DO - 10.1063/1.5038466
M3 - Conference contribution
AN - SCOPUS:85048242555
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 -