A5072662953- Hearing, Cochlea, Tinnitus, Genetics
- Hearing Loss and Rehabilitation
- Noise Effects and Management
- Vestibular and auditory disorders
- Acoustic Wave Phenomena Research
- Ear Surgery and Otitis Media
- Marine animal studies overview
- Congenital heart defects research
- Speech and Audio Processing
- Erythrocyte Function and Pathophysiology
- RNA regulation and disease
- Phonetics and Phonology Research
- Amphibian and Reptile Biology
- Photoacoustic and Ultrasonic Imaging
- Animal Vocal Communication and Behavior
- Animal Behavior and Reproduction
- Optical Coherence Tomography Applications
- Bat Biology and Ecology Studies
University of Southern California
2018-2025
Southern California University for Professional Studies
2021-2024
Stanford University
2016-2018
Northwestern University
2011-2017
Consorci Institut D'Investigacions Biomediques August Pi I Sunyer
2016
University of Chile
2016
Massachusetts Eye and Ear Infirmary
2016
Institució Catalana de Recerca i Estudis Avançats
2016
San Diego State University
2011
Mammalian hearing sensitivity and frequency selectivity depend on a mechanical amplification process mediated by outer hair cells (OHCs). OHCs are situated within the organ of Corti atop basilar membrane (BM), which supports sound-evoked traveling waves. It is well established that generate force to selectively amplify BM waves where they peak, accumulates from one location next over this narrow cochlear region. However, recent measurements demonstrate along apical surface Corti, reticular...
Significance The remarkable high-frequency sensitivity of mammalian hearing depends on the amplification sound-evoked cochlear vibrations by outer hair cells. One way that cells are proposed to generate amplifying forces is through voltage-driven changes in cell length. However, it remains unclear whether this electromotility can work fast enough vivo provide at necessary frequencies. Here, we show sound elicits motions within living mouse cochlea fully consistent with electromotility. These...
Abstract Sensory hair cells, the mechanoreceptors of auditory and vestibular systems, harbor two specialized elaborations apical surface, bundle cuticular plate. In contrast to extensively studied mechanosensory bundle, plate is not as well understood. It believed provide a rigid foundation for stereocilia motion, but specifics about its function, especially significance integrity long-term maintenance cell mechanotransduction, are known. We discovered that protein called LIM only 7 (LMO7)...
The stereociliary bundles of cochlear hair cells convert mechanical vibrations into the electrical signals required for auditory sensation. While stiffness strongly influences mechanotransduction, its influence on vibratory response partition is unclear. To assess this, we measured in mutant mice with reduced bundle or a tectorial membrane (TM) that detached from sensory epithelium. We found reducing decreased high-frequency extent and sharpened tuning responses obtained postmortem....
We describe an optical coherence tomography and vibrometry system designed for portable hand-held usage in the otology clinic on awake patients. The provides clinically relevant point-of-care morphological imaging with 14-44 µm resolution functional vibratory measures sub-nanometer sensitivity. evaluated various new approaches extracting information including a multi-tone stimulus, continuous chirp alternating air bone stimulus. also explored response over area of tympanic membrane (TM)...
The mammalian cochlea receives efferent feedback from the brain. Many functions for this have been hypothesized, including on short timescales, such as mediating attentional states, and long buffering acoustic trauma. Testing these hypotheses has impeded by an inability to make direct measurements of effects in awake animals. Here, we assessed role medial olivocochlear (MOC) nerve fibers cochlear amplification measuring organ Corti vibratory responses sound both sexes anesthetized mice. We...
The purpose was to determine the effect of hearing loss on ability separate competing talkers using talker differences in fundamental frequency (F0) and apparent vocal-tract length (VTL). Performance 13 adults with 6 normal measured Coordinate Response Measure. For listeners loss, speech amplified filtered according NAL-RP aid prescription. Target-to-competition ratios varied from 0 9 dB. target sentence randomly assigned higher or lower values F0 VTL each trial. improved for up semitones...
Neuroplastin (Nptn) is a member of the Ig superfamily and expressed in two isoforms, Np55 Np65. Np65 regulates synaptic transmission but function unknown. In an <i>N</i>-ethyl-<i>N</i>-nitrosaurea mutagenesis screen, we have now generated mouse line with <i>Nptn</i> mutation that causes deafness. We show stereocilia outer hair cells (OHCs) not inner affects interactions tectorial membrane. <i>In vivo</i> vibrometry demonstrates cochlear amplification absent mutant mice, which consistent...
The mammalian ear embeds a cellular amplifier that boosts sound-induced hydromechanical waves as they propagate along the cochlea. operation of this is not fully understood and difficult to disentangle experimentally. In prevailing view, cochlear are amplified by piezo-electric action outer hair cells (OHCs), whose cycle-by-cycle elongations contractions inject power into local motion basilar membrane (BM). Concomitant deformations opposing (or “top”) side organ Corti assumed play minor role...
Abstract The frequency selectivity of the mammalian auditory system is critical for discriminating complex sounds like speech. This derives from sharp tuning cochlea’s mechanical response to sound, which largely attributed amplification cochlear vibrations by outer hair cells (OHCs). Due its nonlinearity, process also leads generation distortion products (DPs), some propagate out ear canal as DP otoacoustic emissions (DPOAEs). However, insight that these signals provide about tuned micro-...
Otoacoustic emissions, sounds generated in the inner ear, have become a convenient non-invasive tool to examine efferent modulation of cochlear mechanics. Activation medial olivocochlear efferents has been shown generally reduce magnitude these emissions. When effects activation on detailed spectral structures emissions examined, shift patterns towards higher frequencies reported for distortion product and spontaneous otoacoustic Stimulus frequency proposed as preferred emission type study...
Behavioral hearing thresholds and otoacoustic emission (OAE) spectra often exhibit quasiperiodic fluctuations with frequency. For behavioral OAE responses to single tones—the latter referred as stimulus-frequency emissions (SFOAEs)—this microstructure has been attributed intracochlear reflections of SFOAE energy between its region generation the middle ear boundary. However, relationship microstructures, well their presumed dependence on properties SFOAE-generation mechanism, have yet be...
When the ear is stimulated by two tones presented at frequencies f1 and f2, nonlinearity in cochlea's vibratory response leads to generation of distortion products (DPs), with cubic 2f1-f2 DP commonly viewed as most prominent. While quadratic f2-f1 also evident numerous physiological perceptual studies, its presence mechanical has been less well documented. Here, examination DPs within mouse cochlea confirmed that was a significant sometimes dominant component, whether were measured near...
When elicited by two stimulus tones (at frequencies f1 and f2, f2 > f1), the amplitudes of specific distortion-product otoacoustic emission (DPOAE) components exhibit a characteristic bandpass shape as ratio between is varied. This has been attributed to various mechanisms including intracochlear resonance, suppression, wave interference, proposed be related cochlear frequency tuning. While human studies suggest modest correlations psychophysical tuning DPOAE amplitude vs. f2/f1 functions,...
Modulation of cochlear mechanics by the medial olivocochlear efferent system is characterized a reduction in active, outer hair cell-mediated amplification basilar membrane motion. This increases thresholds and linearizes input-output functions for low-to-moderate stimulus levels. Significant effects have also been observed responses to higher levels, potentially reflecting changes mechanical properties partition. In humans, sound activated stimulus-frequency otoacoustic emissions used as...
Behavioral pure-tone hearing thresholds and stimulus-frequency otoacoustic emissions (SFOAEs) were measured with a high frequency resolution from 0.5-20 kHz in 15 female participants. Stimuli calibrated terms of forward pressure level (FPL). SFOAE responses to 36 dB FPL probes largest near 1 declined above 8-10 kHz, though still measurable at frequencies approaching 16 some ears. SFOAEs typically dropped amplitude that was roughly one octave below the "corner" audiogram, one-third one-half...
ABSTRACT Cochlear outer hair cells (OHCs) transduce sound-induced vibrations of their stereociliary bundles into receptor potentials that drive changes in cell length. While fast, phasic OHC length are thought to underlie an amplification process required for sensitive hearing, OHCs also exhibit large tonic changes. The origins and functional significance this motility unclear. Here, vivo cochlear vibration measurements reveal tonic, mice with defects impair mechanotransduction eliminate...