Influences of the Cochlear Structure on the Dispersion of Low-Frequency Signals

LI Te; LIU Shao-bao; LI Meng-meng; WU Ying; LI Yue-ming

doi:10.3879/j.issn.1000-0887.2014.08.007

Volume 35 Issue 8

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LI Te, LIU Shao-bao, LI Meng-meng, WU Ying, LI Yue-ming. Influences of the Cochlear Structure on the Dispersion of Low-Frequency Signals[J]. Applied Mathematics and Mechanics, 2014, 35(8): 893-902. doi: 10.3879/j.issn.1000-0887.2014.08.007

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Influences of the Cochlear Structure on the Dispersion of Low-Frequency Signals

doi: 10.3879/j.issn.1000-0887.2014.08.007

State Key Laboratory for Strength and Vibration of Mechanical Structures(Xi’an Jiaotong University), Xi’an 710049, P.R.China

Funds: The National Natural Science Foundation of China(11272242；91016008)

Received Date: 2013-11-19
Publish Date: 2014-08-15

Abstract

Abstract

The cochlea is the most precise mechanical component in a human body. With frequencies from dozens to thousands of Hertz, acoustic signals can be processed by the cochlea and captured by the sensory hair cells on the basilar membrane (BM). Experimental research shows that sound waves of different frequencies are scattered at different positions along the basilar membrane as a natural Fourier filter. In this paper, based on Manoussaki’s 3D fluid-solid coupling model for the spiral cochlear basilar membrane and in addition according to the longitudinal gradients of the cochlear duct height and the BM stiffness, a dispersion equation for the acoustic wave propagation along the basilar membrane was deduced. The influences of the duct height and the BM stiffness on the dispersion characteristics were analyzed. It is found that existence of the cochlear endolymph greatly increases the low frequency signal processing ability, and the capture frequency reduces with the decreases of both the BM stiffness and the duct height. Finally, 3 examples of human, gerbil and guinea pig were empirically studied for verification. 3 frequency-position diagrams corresponding to the 3 animals respectively were obtained to prove the correctness of the proposed dispersion model, and reveal the relationship between the biological adaptability and the function of cochlear dispersion. This study is not only beneficial to understanding of the cochlear function but also promising to lay a theoretical basis for the development and design of sound sensors.
- cochlea,
- basilar membrane,
- low-frequency signal,
- dispersion,
- frequency-position diagram

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References(15)

References

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