TY - JOUR
T1 - The biophysical origin of traveling-wave dispersion in the cochlea
AU - Ramamoorthy, Sripriya
AU - Zha, Ding Jun
AU - Nuttall, Alfred L.
N1 - Funding Information:
This work was supported by National Institutes of Health grant NIDCD DC 00141.
PY - 2010
Y1 - 2010
N2 - Sound processing begins at the peripheral auditory system, where it undergoes a highly complex transformation and spatial separation of the frequency components inside the cochlea. This sensory signal processing constitutes a neurophys-iological basis for psychoacoustics. Wave propagation in the cochlea, as shown by measurements of basilar membrane velocity and auditory nerve responses to sound, has demonstrated significant frequency modulation (dispersion), in addition to tonotopic gain and active amplification. The physiological and physical basis for this dispersion remains elusive. In this article, a simple analytical model is presented, along with experimental validation using physiological measurements from guinea pigs, to identify the origin of traveling-wave dispersion in the cochlea. We show that dispersion throughout the cochlea is fundamentally due to the coupled fluid-structure interaction between the basilar membrane and the scala fluids. It is further influenced by the variation in physical and geometrical properties of the basilar membrane, the sensitivity or gain of the hearing organ, and the relative dominance of the compression mode at about one-third octave beyond the best frequency.
AB - Sound processing begins at the peripheral auditory system, where it undergoes a highly complex transformation and spatial separation of the frequency components inside the cochlea. This sensory signal processing constitutes a neurophys-iological basis for psychoacoustics. Wave propagation in the cochlea, as shown by measurements of basilar membrane velocity and auditory nerve responses to sound, has demonstrated significant frequency modulation (dispersion), in addition to tonotopic gain and active amplification. The physiological and physical basis for this dispersion remains elusive. In this article, a simple analytical model is presented, along with experimental validation using physiological measurements from guinea pigs, to identify the origin of traveling-wave dispersion in the cochlea. We show that dispersion throughout the cochlea is fundamentally due to the coupled fluid-structure interaction between the basilar membrane and the scala fluids. It is further influenced by the variation in physical and geometrical properties of the basilar membrane, the sensitivity or gain of the hearing organ, and the relative dominance of the compression mode at about one-third octave beyond the best frequency.
UR - http://www.scopus.com/inward/record.url?scp=77957357292&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77957357292&partnerID=8YFLogxK
U2 - 10.1016/j.bpj.2010.07.004
DO - 10.1016/j.bpj.2010.07.004
M3 - Article
C2 - 20858412
AN - SCOPUS:77957357292
SN - 0006-3495
VL - 99
SP - 1687
EP - 1695
JO - Biophysical Journal
JF - Biophysical Journal
IS - 6
ER -