{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/29677"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/29677","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"A feedback analysis of outer hair cell dynamics","abstract":"Outer hair cells (OHCs) generate active forces in the mammalian cochlea. Acting as cochlear amplifiers, OHCs can counteract viscous drag, generating high gain at characteristic frequencies and allowing for the sharp frequency selectivity and sensitivity observed in mammals. Excitatory displacement of the basilar membrane causes depolarization of OHC membrane potentials which results in contraction. The motor protein prestin is driven by receptor potentials. However, low-pass filtering by the plasma membrane should severely attenuate the receptor potential at high frequencies (> 100 kHz) where mammalian hearing has been observed. Thus, an open question is how OHCs can respond at these high frequencies despite their low frequency cutoff. Inspired by the use of feedback in mechanical and electrical systems to accelerate slow poles, I demonstrate that negative feedback from the coupling of two mechanical modes of vibration can lead to a membrane time constant speedup and a sharpening of the mechanical response.","abstract_html":"Outer hair cells (OHCs) generate active forces in the mammalian cochlea. Acting as cochlear amplifiers, OHCs can counteract viscous drag, generating high gain at characteristic frequencies and allowing for the sharp frequency selectivity and sensitivity observed in mammals. Excitatory displacement of the basilar membrane causes depolarization of OHC membrane potentials which results in contraction. The motor protein prestin is driven by receptor potentials. However, low-pass filtering by the plasma membrane should severely attenuate the receptor potential at high frequencies (> 100 kHz) where mammalian hearing has been observed. Thus, an open question is how OHCs can respond at these high frequencies despite their low frequency cutoff. Inspired by the use of feedback in mechanical and electrical systems to accelerate slow poles, I demonstrate that negative feedback from the coupling of two mechanical modes of vibration can lead to a membrane time constant speedup and a sharpening of the mechanical response.","abstract_has_math":false,"creators":["Lu, Timothy K. (Timothy Kuan-Ta), 1981-"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.","school":null,"contributors":[],"advisors":["Rahul Sarpeshkar."],"committee_chairs":[],"committee_members":[],"year":2003,"date_issued":"2003","date_published":"2003","updated_at":"2026-07-22T22:21:47Z","subjects":["Electrical Engineering and Computer Science."],"languages":["eng"],"rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/29677","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Rahul Sarpeshkar."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science."]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science."]},{"key":"dc:creator","label":"Author","values":["Lu, Timothy K. 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They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://dspace.mit.edu/handle/1721.1/7582"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1721.1/29677"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.","Includes bibliographical references (leaves 144-146)."]},{"key":"dc:description.abstract","label":"Abstract","values":["Outer hair cells (OHCs) generate active forces in the mammalian cochlea. Acting as cochlear amplifiers, OHCs can counteract viscous drag, generating high gain at characteristic frequencies and allowing for the sharp frequency selectivity and sensitivity observed in mammals. Excitatory displacement of the basilar membrane causes depolarization of OHC membrane potentials which results in contraction. The motor protein prestin is driven by receptor potentials. However, low-pass filtering by the plasma membrane should severely attenuate the receptor potential at high frequencies (> 100 kHz) where mammalian hearing has been observed. Thus, an open question is how OHCs can respond at these high frequencies despite their low frequency cutoff. 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(Timothy Kuan-Ta), 1981-"],"dc:date.accessioned":["2006-03-24T16:14:19Z"],"dc:date.available":["2006-03-24T16:14:19Z"],"dc:date.issued":["2003"],"dc:description":["Thesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.","Includes bibliographical references (leaves 144-146)."],"dc:description.abstract":["Outer hair cells (OHCs) generate active forces in the mammalian cochlea. Acting as cochlear amplifiers, OHCs can counteract viscous drag, generating high gain at characteristic frequencies and allowing for the sharp frequency selectivity and sensitivity observed in mammals. Excitatory displacement of the basilar membrane causes depolarization of OHC membrane potentials which results in contraction. The motor protein prestin is driven by receptor potentials. However, low-pass filtering by the plasma membrane should severely attenuate the receptor potential at high frequencies (> 100 kHz) where mammalian hearing has been observed. Thus, an open question is how OHCs can respond at these high frequencies despite their low frequency cutoff. Inspired by the use of feedback in mechanical and electrical systems to accelerate slow poles, I demonstrate that negative feedback from the coupling of two mechanical modes of vibration can lead to a membrane time constant speedup and a sharpening of the mechanical response."],"dc:description.degree":["M.Eng.and S.B."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/1721.1/29677"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Electrical Engineering and Computer Science."],"dc:title":["A feedback analysis of outer hair cell dynamics"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:21:47Z"}