dc.contributor.advisor | Nakajima, Heidi | |
dc.contributor.advisor | Rosowski, John J. | |
dc.contributor.author | Bowers, Peter N. | |
dc.date.accessioned | 2020-09-15T10:29:01Z | |
dc.date.created | 2020-03 | |
dc.date.issued | 2020-01-09 | |
dc.date.submitted | 2020 | |
dc.identifier.citation | Bowers, Peter N. 2020. Characterization of Bone-Conduction Mechanisms in Chinchilla Using in Vivo Measurements and Impedance Models. Doctoral dissertation, Harvard University, Graduate School of Arts & Sciences. | |
dc.identifier.uri | https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37365107 | * |
dc.description.abstract | The mechanisms of bone-conduction hearing in chinchilla that result from vibration of the skull, include ear-canal compression, relative motion between the middle-ear bones and the inner ear, compression of the cochlear bone, and the transmission of intracranial sound pressures into the inner ear via fluid-filled connecting pathways. This work aims to characterize these mechanisms in terms of the magnitude and phase of vibration-driven sound pressure and volume-velocity sources within the auditory periphery. A lumped-element circuit model of air-conduction hearing in chinchilla is developed, which serves as the basis for our bone-conduction model. The air-conduction model is adapted from a model of hearing in humans, developed by Zwislocki (1962). The chinchilla model is extended by the addition of an ear canal that both contains multiple external-ear bone-conduction sources, and imposes natural impedances on motions of the TM produced by vibration-driven sources within the external, middle and inner ear. The model is further modified by the addition of realistic cochlear scalae, a helicotrema and vestibular and cochlear aqueducts, all of which are defined by the analysis of micro-CT scans of a chinchilla ear. The multiple vibration-driven bone-conduction sources are characterized by measurements of vibration-induced mechanical, acoustic, and/or neurological responses, in normal- or manipulated-ear conditions. The measurements under the various conditions enable separation of system responses resulting from individual sources. Two external-ear bone-conduction sources, which define the contribution of the bony and cartilaginous walls of the ear canal to vibration-driven sound pressures within the canal, are fully characterized. These sources are shown to dominate the vibration-induced sound pressures within the ear canal. The effect of vibration-driven intracranial sound pressures transmitted to the inner ear via the vestibular and cochlear aqueducts is estimated from measurements and the model. Our analyses suggest this mechanism does not play a significant role in vibration-induced hearing mechanics. A method for differentiating the contributions of cochlear compression and cochlear-fluid inertia to bone-conduction hearing is offered, and an application of this method is demonstrated using a proposed cochlear network that includes such mechanisms. | |
dc.description.sponsorship | Medical Sciences | |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | |
dash.license | LAA | |
dc.subject | bone-conduction hearing | |
dc.subject | circuit model | |
dc.subject | chinchilla | |
dc.subject | middle ear | |
dc.title | Characterization of Bone-Conduction Mechanisms in Chinchilla Using in Vivo Measurements and Impedance Models | |
dc.type | Thesis or Dissertation | |
dash.depositing.author | Bowers, Peter N. | |
dc.date.available | 2020-09-15T10:29:01Z | |
thesis.degree.date | 2020 | |
thesis.degree.grantor | Graduate School of Arts & Sciences | |
thesis.degree.grantor | Graduate School of Arts & Sciences | |
thesis.degree.level | Doctoral | |
thesis.degree.level | Doctoral | |
thesis.degree.name | Doctor of Philosophy | |
thesis.degree.name | Doctor of Philosophy | |
dc.contributor.committeeMember | Cheng, Tao | |
dc.contributor.committeeMember | Remenschneider, Aaron | |
dc.contributor.committeeMember | Freeman, Dennis | |
dc.type.material | text | |
thesis.degree.department | Medical Sciences | |
thesis.degree.department | Medical Sciences | |
dash.identifier.vireo | | |
dash.author.email | pnbsake@gmail.com | |