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Karosas DM, Gonzales L, Wang Y, Bergevin C, Carney LH, Henry KS. Otoacoustic emissions predict cochlear-nerve but not behavioral frequency tuning in an avian vocal-communication specialist. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.29.610326. [PMID: 39257830 PMCID: PMC11383700 DOI: 10.1101/2024.08.29.610326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Frequency analysis by the cochlea forms a key foundation for all subsequent auditory processing. Stimulus-frequency otoacoustic emissions (SFOAEs) are a potentially powerful alternative to traditional behavioral experiments for estimating cochlear tuning without invasive testing, as is necessary in humans. Which methods accurately predict cochlear tuning remains controversial due to only a single animal study comparing SFOAE-based, behavioral, and cochlear frequency tuning in the same species. The budgerigar is a parakeet species with human-like behavioral sensitivity to many sounds and the capacity to mimic speech. Multiple studies show that budgerigars exhibit a perceptual "auditory fovea" with sharpest behavioral frequency tuning at mid frequencies from 3.5-4 kHz, in contrast to the typical pattern of monotonically increasing tuning sharpness for higher characteristic frequencies. We measured SFOAE-based and cochlear-afferent tuning in budgerigars, for comparison to previously reported behavioral results. SFOAE-based and cochlear-afferent tuning sharpness both increased monotonically for higher frequencies, in contrast to the behavioral pattern. Thus, SFOAE-based tuning in budgerigars accurately predicted cochlear tuning, and both measures aligned with typical patterns of cochlear frequency tuning in other species. Given divergent behavioral tuning in the budgerigars, which could reflect specializations for central processing of masked signals, these results highlight the value of SFOAEs for estimating cochlear tuning and caution against direct inference of cochlear tuning from behavioral results.
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Wit HP, Bell A. Something in Our Ears Is Oscillating, but What? A Modeller's View of Efforts to Model Spontaneous Emissions. J Assoc Res Otolaryngol 2024; 25:313-328. [PMID: 38710871 PMCID: PMC11349976 DOI: 10.1007/s10162-024-00940-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 02/26/2024] [Indexed: 05/08/2024] Open
Abstract
When David Kemp discovered "spontaneous ear noise" in 1978, it opened up a whole new perspective on how the cochlea works. The continuous tonal sound emerging from most healthy human ears, now called spontaneous otoacoustic emissions or SOAEs, was an unmistakable sign that our hearing organ must be considered an active detector, not just a passive microphone, just as Thomas Gold had speculated some 30 years earlier. Clearly, something is oscillating as a byproduct of that sensitive inbuilt detector, but what exactly is it? Here, we give a chronological account of efforts to model SOAEs as some form of oscillator, and at intervals, we illustrate key concepts with numerical simulations. We find that after many decades there is still no consensus, and the debate extends to whether the oscillator is local, confined to discrete local sources on the basilar membrane, or global, in which an assembly of micro-mechanical elements and basilar membrane sections, coupled by inner ear fluid, interact over a wide region. It is also undecided whether the cochlear oscillator is best described in terms of the well-known Van der Pol oscillator or the less familiar Duffing or Hopf oscillators. We find that irregularities play a key role in generating the emissions. This paper is not a systematic review of SOAEs and their properties but more a historical survey of the way in which various oscillator configurations have been applied to modelling human ears. The conclusion is that the difference between the local and global approaches is not clear-cut, and they are probably not mutually exclusive concepts. Nevertheless, when one sees how closely human SOAEs can be matched to certain arrangements of oscillators, Gold would no doubt say we are on the right track.
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Affiliation(s)
- Hero P Wit
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.
- Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Groningen, Netherlands.
| | - Andrew Bell
- John Curtin School of Medical Research, The Australian National University, Canberra, Australia
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Manley GA. Conditions Underlying the Appearance of Spontaneous Otoacoustic Emissions in Mammals. J Assoc Res Otolaryngol 2024; 25:303-311. [PMID: 38760548 PMCID: PMC11349964 DOI: 10.1007/s10162-024-00950-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 04/28/2024] [Indexed: 05/19/2024] Open
Abstract
Across the wide range of land vertebrate species, spontaneous otoacoustic emissions (SOAE) are common, but not always found. The reasons for the differences between species of the various groups in their emission patterns are often not well understood, particularly within mammals. This review examines the question as to what determines in mammals whether SOAE are emitted or not, and suggests that the coupling between hair-cell regions diminishes when the space constant of frequency distribution becomes larger. The reduced coupling is assumed to result in a greater likelihood of SOAE being emitted.
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Affiliation(s)
- Geoffrey A Manley
- Cochlear and Auditory Brainstem Physiology, Department of Neuroscience, School of Medicine and Health Sciences, Cluster of Excellence "Hearing4all", Carl von Ossietzky University Oldenburg, 26129, Oldenburg, Germany.
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Shera CA. Swept Along: Measuring Otoacoustic Emissions Using Continuously Varying Stimuli. J Assoc Res Otolaryngol 2024; 25:91-102. [PMID: 38409555 PMCID: PMC11018600 DOI: 10.1007/s10162-024-00934-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/31/2024] [Indexed: 02/28/2024] Open
Abstract
At the 2004 Midwinter Meeting of the Association for Research in Otolaryngology, Glenis Long and her colleagues introduced a method for measuring distortion-product otoacoustic emissions (DPOAEs) using primary-tone stimuli whose instantaneous frequencies vary continuously with time. In contrast to standard OAE measurement methods, in which emissions are measured in the sinusoidal steady state using discrete tones of well-defined frequency, the swept-tone method sweeps across frequency, often at rates exceeding 1 oct/s. The resulting response waveforms are then analyzed using an appropriate filter (e.g., by least-squares fitting). Although introduced as a convenient way of studying DPOAE fine structure by separating the total OAE into distortion and reflection components, the swept-tone method has since been extended to stimulus-frequency emissions and has proved an efficient and valuable tool for probing cochlear mechanics. One day-a long time coming-swept tones may even find their way into the audiology clinic.
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Affiliation(s)
- Christopher A Shera
- Caruso Department of Otolaryngology, University of Southern California, Los Angeles, CA, 90033, USA.
- Department of Physics & Astronomy, University of Southern California, Los Angeles, CA, 90033, USA.
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Shera CA. Whistling While it Works: Spontaneous Otoacoustic Emissions and the Cochlear Amplifier. J Assoc Res Otolaryngol 2022; 23:17-25. [PMID: 34981262 PMCID: PMC8782959 DOI: 10.1007/s10162-021-00829-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/01/2021] [Indexed: 02/03/2023] Open
Abstract
Perhaps the most striking evidence for active processes operating within the inner ears of mammals and non-mammals alike is their ability to spontaneously produce sound. Predicted by Thomas Gold in 1948, some 30 years prior to their discovery, the narrow-band sounds now known as spontaneous otoacoustic emissions (SOAEs) remain incompletely understood, their origins controversial. Without a single equation in the main text, we review the essential concepts underlying the "local-" and "global-oscillator" frameworks for understanding SOAE generation. Comparing their key assumptions and predictions, we relate the two frameworks to unresolved questions about the biophysical mechanisms of cochlear amplification.
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Affiliation(s)
- Christopher A Shera
- Caruso Department of Otolaryngology and Department of Physics & Astronomy, University of Southern California, California, Los Angeles, 90033, USA.
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Faber J, Bozovic D. Chimera states and frequency clustering in systems of coupled inner-ear hair cells. CHAOS (WOODBURY, N.Y.) 2021; 31:073142. [PMID: 34340330 DOI: 10.1063/5.0056848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
Coupled hair cells of the auditory and vestibular systems perform the crucial task of converting the energy of sound waves and ground-borne vibrations into ionic currents. We mechanically couple groups of living, active hair cells with artificial membranes, thus mimicking in vitro the coupled dynamical system. We identify chimera states and frequency clustering in the dynamics of these coupled nonlinear, autonomous oscillators. We find that these dynamical states can be reproduced by our numerical model with heterogeneity of the parameters. Furthermore, we find that this model is most sensitive to external signals when poised at the onset of synchronization, where chimera and cluster states are likely to form. We, therefore, propose that the partial synchronization in our experimental system is a manifestation of a system poised at the verge of synchronization with optimal sensitivity.
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Affiliation(s)
- Justin Faber
- Department of Physics & Astronomy, University of California, Los Angeles, Los Angeles, California 90095, USA
| | - Dolores Bozovic
- Department of Physics & Astronomy, University of California, Los Angeles, Los Angeles, California 90095, USA
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Bergevin C, Mason A, Mhatre N. Evidence supporting synchrony between two active ears due to interaural coupling. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:EL25. [PMID: 32006966 DOI: 10.1121/10.0000473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 12/08/2019] [Indexed: 06/10/2023]
Abstract
Motivated by recent developments suggesting that interaural coupling in non-mammals allows for the two active ears to effectively synchronize, this report describes otoacoustic measurements made in the oral cavity of lizards. As expected from that model, spontaneous otoacoustic emissions (SOAEs) were readily measurable in the mouth, which is contiguous with the interaural airspace. Additionally, finite element model calculations were made to simulate the interaural acoustics based upon SOAE-related tympanic membrane vibrational data. Taken together, these data support the notion of two active ears synchronizing by virtue of acoustic coupling and have potential implications for sound localization at low-levels.
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Affiliation(s)
- Christopher Bergevin
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J1P3, Canada
| | - Andrew Mason
- Department of Biology, University of Toronto, Scarborough, Ontario M1C 1A4, Canada
| | - Natasha Mhatre
- Department of Biology, Western University, London, Ontario N6A 5B7, , ,
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Wit HP, Manley GA, van Dijk P. Modeling the characteristics of spontaneous otoacoustic emissions in lizards. Hear Res 2019; 385:107840. [PMID: 31760263 DOI: 10.1016/j.heares.2019.107840] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 11/01/2019] [Accepted: 11/02/2019] [Indexed: 11/19/2022]
Abstract
Lizard auditory papillae have proven to be an attractive object for modelling the production of spontaneous otoacoustic emissions (SOAE). Here we use an established model (Vilfan and Duke, 2008) and extend it by exploring the effect of varying the number of oscillating elements, the strength of the parameters that describe the coupling between oscillators, the strength of the oscillators, and additive noise. The most remarkable result is that the actual number of oscillating elements hardly influences the spectral pattern, explaining why spectra from very different papillar dimensions are similar. Furthermore, the spacing between spectral peaks primarily depends on the reactive coupling between the oscillator elements. This is consistent with observed differences between lizard species with respect to tectorial covering of hair cells and SOAE peak spacings. Thus, the model provides a basic understanding of the variation in SOAE properties across lizard species.
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Affiliation(s)
- Hero P Wit
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, Groningen, the Netherlands; University of Groningen, Graduate School of Medical Sciences (Research School of Behavioral and Cognitive Neurosciences), Groningen, the Netherlands.
| | - Geoffrey A Manley
- Cochlear and Auditory Brainstem Physiology, Department of Neuroscience, School of Medicine and Health Sciences, Cluster of Excellence "Hearing4all", Research Center Neuroscience, Carl von Ossietzky University Oldenburg, 26129, Oldenburg, Germany
| | - P van Dijk
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, Groningen, the Netherlands; University of Groningen, Graduate School of Medical Sciences (Research School of Behavioral and Cognitive Neurosciences), Groningen, the Netherlands
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Engler S, Köppl C, Manley GA, de Kleine E, van Dijk P. Suppression tuning of spontaneous otoacoustic emissions in the barn owl (Tyto alba). Hear Res 2019; 385:107835. [PMID: 31710933 DOI: 10.1016/j.heares.2019.107835] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 09/30/2019] [Accepted: 10/27/2019] [Indexed: 11/20/2022]
Abstract
Spontaneous otoacoustic emissions (SOAEs) have been observed in a variety of different vertebrates, including humans and barn owls (Tyto alba). The underlying mechanisms producing the SOAEs and the meaning of their characteristics regarding the frequency selectivity of an individual and species are, however, still under debate. In the present study, we measured SOAE spectra in lightly anesthetized barn owls and suppressed their amplitudes by presenting pure tones at different frequencies and sound levels. Suppression effects were quantified by deriving suppression tuning curves (STCs) with a criterion of 2 dB suppression. SOAEs were found in 100% of ears (n = 14), with an average of 12.7 SOAEs per ear. Across the whole SOAE frequency range of 3.4-10.2 kHz, the distances between neighboring SOAEs were relatively uniform, with a median distance of 430 Hz. The majority (87.6%) of SOAEs were recorded at frequencies that fall within the barn owl's auditory fovea (5-10 kHz). The STCs were V-shaped and sharply tuned, similar to STCs from humans and other species. Between 5 and 10 kHz, the median Q10dB value of STC was 4.87 and was thus lower than that of owl single-unit neural data. There was no evidence for secondary STC side lobes, as seen in humans. The best thresholds of the STCs varied from 7.0 to 57.5 dB SPL and correlated with SOAE level, such that smaller SOAEs tended to require a higher sound level to be suppressed. While similar, the frequency-threshold curves of auditory-nerve fibers and STCs of SOAEs differ in some respects in their tuning characteristics indicating that SOAE suppression tuning in the barn owl may not directly reflect neural tuning in primary auditory nerve fibers.
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Affiliation(s)
- Sina Engler
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, The Netherlands; Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neurosciences, University of Groningen, The Netherlands.
| | - Christine Köppl
- Cluster of Excellence "Hearing4all" and Research Centre Neurosensory Science, Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky University Oldenburg, 26129, Oldenburg, Germany
| | - Geoffrey A Manley
- Cluster of Excellence "Hearing4all" and Research Centre Neurosensory Science, Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky University Oldenburg, 26129, Oldenburg, Germany
| | - Emile de Kleine
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, The Netherlands; Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neurosciences, University of Groningen, The Netherlands
| | - Pim van Dijk
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, The Netherlands; Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neurosciences, University of Groningen, The Netherlands
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10
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Roongthumskul Y, Ó Maoiléidigh D, Hudspeth AJ. Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears. Biophys J 2019; 116:2023-2034. [PMID: 31010667 PMCID: PMC6531668 DOI: 10.1016/j.bpj.2019.02.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/08/2019] [Accepted: 02/28/2019] [Indexed: 11/03/2022] Open
Abstract
Spontaneous otoacoustic emissions (SOAEs) are weak sounds that emanate from the ears of tetrapods in the absence of acoustic stimulation. These emissions are an epiphenomenon of the inner ear's active process, which enhances the auditory system's sensitivity to weak sounds, but their mechanism of production remains a matter of debate. We recorded SOAEs simultaneously from the two ears of the tokay gecko and found that binaural emissions could be strongly correlated: some emissions occurred at the same frequency in both ears and were highly synchronized. Suppression of the emissions in one ear often changed the amplitude or shifted the frequency of emissions in the other. Decreasing the frequency of emissions from one ear by lowering its temperature usually reduced the frequency of the contralateral emissions. To understand the relationship between binaural SOAEs, we developed a mathematical model of the eardrums as noisy nonlinear oscillators coupled by the air within an animal's mouth. By according with the model, the results indicate that some SOAEs are generated bilaterally through acoustic coupling across the oral cavity. The model predicts that sound localization through the acoustic coupling between ears is influenced by the active processes of both ears.
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Affiliation(s)
- Yuttana Roongthumskul
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, New York
| | - Dáibhid Ó Maoiléidigh
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, New York; Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California
| | - A J Hudspeth
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, New York.
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Sumner CJ, Wells TT, Bergevin C, Sollini J, Kreft HA, Palmer AR, Oxenham AJ, Shera CA. Mammalian behavior and physiology converge to confirm sharper cochlear tuning in humans. Proc Natl Acad Sci U S A 2018; 115:11322-11326. [PMID: 30322908 PMCID: PMC6217411 DOI: 10.1073/pnas.1810766115] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Frequency analysis of sound by the cochlea is the most fundamental property of the auditory system. Despite its importance, the resolution of this frequency analysis in humans remains controversial. The controversy persists because the methods used to estimate tuning in humans are indirect and have not all been independently validated in other species. Some data suggest that human cochlear tuning is considerably sharper than that of laboratory animals, while others suggest little or no difference between species. We show here in a single species (ferret) that behavioral estimates of tuning bandwidths obtained using perceptual masking methods, and objective estimates obtained using otoacoustic emissions, both also employed in humans, agree closely with direct physiological measurements from single auditory-nerve fibers. Combined with human behavioral data, this outcome indicates that the frequency analysis performed by the human cochlea is of significantly higher resolution than found in common laboratory animals. This finding raises important questions about the evolutionary origins of human cochlear tuning, its role in the emergence of speech communication, and the mechanisms underlying our ability to separate and process natural sounds in complex acoustic environments.
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Affiliation(s)
- Christian J Sumner
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, NG7 2RD Nottingham, United Kingdom;
| | - Toby T Wells
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, NG7 2RD Nottingham, United Kingdom
| | - Christopher Bergevin
- Department of Physics & Astronomy, York University, Toronto, ON M3J 1P3, Canada
- Centre for Vision Research, York University, Toronto, ON M3J 1P3, Canada
| | - Joseph Sollini
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, NG7 2RD Nottingham, United Kingdom
| | - Heather A Kreft
- Department of Psychology, University of Minnesota, Minneapolis, MN 55455
- Department of Otolaryngology, University of Minnesota, Minneapolis, MN 55455
| | - Alan R Palmer
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, NG7 2RD Nottingham, United Kingdom
| | - Andrew J Oxenham
- Department of Psychology, University of Minnesota, Minneapolis, MN 55455
- Department of Otolaryngology, University of Minnesota, Minneapolis, MN 55455
| | - Christopher A Shera
- Caruso Department of Otolaryngology, University of Southern California, Los Angeles, CA 90033
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089
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12
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No otoacoustic evidence for a peripheral basis of absolute pitch. Hear Res 2018; 370:201-208. [PMID: 30190151 DOI: 10.1016/j.heares.2018.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/31/2018] [Accepted: 08/06/2018] [Indexed: 11/21/2022]
Abstract
Absolute pitch (AP) is the ability to identify the perceived pitch of a sound without an external reference. Relatively rare, with an incidence of approximately 1/10,000, the mechanisms underlying AP are not well understood. This study examined otoacoustic emissions (OAEs) to determine if there is evidence of a peripheral (i.e., cochlear) basis for AP. Two OAE types were examined: spontaneous emissions (SOAEs) and stimulus-frequency emissions (SFOAEs). Our motivations to explore a peripheral foundation for AP were several-fold. First is the observation that pitch judgment accuracy has been reported to decrease with age due to age-dependent physiological changes cochlear biomechanics. Second is the notion that SOAEs, which are indirectly related to perception, could act as a fixed frequency reference. Third, SFOAE delays, which have been demonstrated to serve as a proxy measure for cochlear frequency selectivity, could indicate tuning differences between groups. These led us to the hypotheses that AP subjects would (relative to controls) exhibit a. greater SOAE activity and b. sharper cochlear tuning. To test these notions, measurements were made in normal-hearing control (N = 33) and AP-possessor (N = 20) populations. In short, no substantial difference in SOAE activity was found between groups, indicating no evidence for one or more strong SOAEs that could act as a fixed cue. SFOAE phase-gradient delays, measured at several different probe levels (20-50 dB SPL), also showed no significant differences between groups. This observation argues against sharper cochlear frequency selectivity in AP subjects. Taken together, these data support the prevailing view that AP mechanisms predominantly arise at a processing level in the central nervous system (CNS) at the brainstem or higher, not within the cochlea.
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Manley GA, Wartini A, Schwabedissen G, Siegl E. Spontaneous otoacoustic emissions in teiid lizards. Hear Res 2018; 363:98-108. [PMID: 29551307 DOI: 10.1016/j.heares.2018.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 02/21/2018] [Accepted: 03/09/2018] [Indexed: 11/17/2022]
Abstract
SOAE from the last major lizard family not yet systematically investigated, the teiids, were collected from the genera Callopistes, Tupinambis and Cnemidophorus. Although their papillae show characteristics of the family Teiidae, the papillae differ both in their size and in the arrangement of uni- and bi-directional hair-cell areas. Among these three genera, Callopistes showed few (2 or 3) SOAE peaks, whereas the other two genera showed more (up to 6 per ear). In the absence of knowledge of the tonotopic maps, however, it was not possible to clearly relate the spectral patterns to the differences in papillar anatomy, suggesting that the determinants of these patterns may be more subtle than anticipated.
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Affiliation(s)
- Geoffrey A Manley
- Cochlear and Auditory Brainstem Physiology, Department of Neuroscience, School of Medicine and Health Sciences, Cluster of Excellence "Hearing4all", Research Centre Neurosensory Science, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany; Lehrstuhl für Zoologie, Technische Universität München, 85354 Freising-Weihenstephan, Germany.
| | - Andrea Wartini
- Lehrstuhl für Zoologie, Technische Universität München, 85354 Freising-Weihenstephan, Germany.
| | - Gabriele Schwabedissen
- Lehrstuhl für Zoologie, Technische Universität München, 85354 Freising-Weihenstephan, Germany.
| | - Elke Siegl
- Lehrstuhl für Zoologie, Technische Universität München, 85354 Freising-Weihenstephan, Germany.
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Biswal M, Mishra SK. Comparison of time-frequency methods for analyzing stimulus frequency otoacoustic emissions. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:626. [PMID: 29495731 PMCID: PMC5796829 DOI: 10.1121/1.5022783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Stimulus frequency otoacoustic emissions (SFOAEs) can have multiple time varying components, including multiple internal reflections. It is, therefore, necessary to study SFOAEs using techniques that can represent their time-frequency behavior. Although various time-frequency schemes can be applied to identify and filter SFOAE components, their accuracy for SFOAE analysis has not been investigated. The relative performance of these methods is important for accurate characterization of SFOAEs that may, in turn, enhance the understanding of SFOAE generation. This study using in silico experiments examined the performance of three linear (short-time Fourier transform, continuous wavelet transform, Stockwell transform) and two nonlinear (empirical mode decomposition and synchrosqueezed wavelet transform) time-frequency approaches for SFOAE analysis. Their performances in terms of phase-gradient delay estimation, frequency specificity, and spectral component extraction are compared, and the relative merits and limitations of each method are discussed. Overall, this paper provides a comparative analysis of various time-frequency methods useful for otoacoustic emission applications.
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Affiliation(s)
- Milan Biswal
- Department of Communication Disorders, New Mexico State University, Las Cruces, New Mexico 88003, USA
| | - Srikanta K Mishra
- Department of Communication Disorders, New Mexico State University, Las Cruces, New Mexico 88003, USA
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15
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Dewey JB, Dhar S. A common microstructure in behavioral hearing thresholds and stimulus-frequency otoacoustic emissions. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:3069. [PMID: 29195446 PMCID: PMC5693793 DOI: 10.1121/1.5009562] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 08/16/2017] [Accepted: 10/16/2017] [Indexed: 06/07/2023]
Abstract
Behavioral hearing thresholds and otoacoustic emission (OAE) spectra often exhibit quasiperiodic fluctuations with frequency. For behavioral and OAE responses to single tones-the latter referred to as stimulus-frequency otoacoustic emissions (SFOAEs)-this microstructure has been attributed to intracochlear reflections of SFOAE energy between its region of generation and the middle ear boundary. However, the relationship between behavioral and SFOAE microstructures, as well as their presumed dependence on the properties of the SFOAE-generation mechanism, have yet to be adequately examined. To address this, behavioral thresholds and SFOAEs evoked by near-threshold tones were compared in 12 normal-hearing female subjects. The microstructures observed in thresholds and both SFOAE amplitudes and delays were found to be strikingly similar. SFOAE phase accumulated an integer number of cycles between the frequencies of microstructure maxima, consistent with a dependence of microstructure periodicity on SFOAE propagation delays. Additionally, microstructure depth was correlated with SFOAE magnitude in a manner resembling that predicted by the intracochlear reflection framework, after assuming reasonable values of parameters related to middle ear transmission. Further exploration of this framework may yield more precise estimates of such parameters and provide insight into their frequency dependence.
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Affiliation(s)
- James B Dewey
- Roxelyn & Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, 2240 Campus Drive, Evanston, Illinois 60208, USA
| | - Sumitrajit Dhar
- Roxelyn & Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, 2240 Campus Drive, Evanston, Illinois 60208, USA
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16
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Xia A, Liu X, Raphael PD, Applegate BE, Oghalai JS. Hair cell force generation does not amplify or tune vibrations within the chicken basilar papilla. Nat Commun 2016; 7:13133. [PMID: 27796310 PMCID: PMC5095595 DOI: 10.1038/ncomms13133] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 09/07/2016] [Indexed: 12/22/2022] Open
Abstract
Frequency tuning within the auditory papilla of most non-mammalian species is electrical, deriving from ion-channel resonance within their sensory hair cells. In contrast, tuning within the mammalian cochlea is mechanical, stemming from active mechanisms within outer hair cells that amplify the basilar membrane travelling wave. Interestingly, hair cells in the avian basilar papilla demonstrate both electrical resonance and force-generation, making it unclear which mechanism creates sharp frequency tuning. Here, we measured sound-induced vibrations within the apical half of the chicken basilar papilla in vivo and found broadly-tuned travelling waves that were not amplified. However, distortion products were found in live but not dead chickens. These findings support the idea that avian hair cells do produce force, but that their effects on vibration are small and do not sharpen tuning. Therefore, frequency tuning within the apical avian basilar papilla is not mechanical, and likely derives from hair cell electrical resonance. The avian auditory papilla has many similarities to the mammalian cochlea but whether force generation by hair cells amplifies the travelling wave, as it does in mammals, remains unknown. Here the authors show that the chicken basilar papilla does not have a ‘cochlear amplifier' and that sharp frequency tuning does not derive from mechanical vibrations.
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Affiliation(s)
- Anping Xia
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, California 94305, USA
| | - Xiaofang Liu
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, California 94305, USA.,Department of Anorectal Surgery, the First Affiliated hospital of China Medical University, 155 NanjingBei Street, ShenYang, LiaoNing Province 110001, China
| | - Patrick D Raphael
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, California 94305, USA
| | - Brian E Applegate
- Department of Biomedical Engineering, Texas A&M University, 5059 Emerging Technology Building, 3120 TAMU, College Station, Texas 77843, USA
| | - John S Oghalai
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, 801 Welch Road, Stanford, California 94305, USA
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17
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Mishra SK, Dinger Z. Influence of medial olivocochlear efferents on the sharpness of cochlear tuning estimates in children. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:1060. [PMID: 27586737 DOI: 10.1121/1.4960550] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The present study objectively quantified the efferent-induced changes in the sharpness of cochlear tuning estimates and compared these alterations in cochlear tuning between adults and children. Click evoked otoacoustic emissions with and without contralateral broadband noise were recorded from 15 young adults and 14 children aged between 5 and 10 yrs. Time-frequency distributions of click evoked otoacoustic emissions were obtained via the S-transform, and the otoacoustic emission latencies were used to estimate the sharpness of cochlear tuning. Contralateral acoustic stimulation caused a significant reduction in the sharpness of cochlear tuning estimates in the low to mid frequency region, but had no effect in the higher frequencies (3175 and 4000 Hz). The magnitude of efferent-induced changes in cochlear tuning estimates was similar between adults and children. The current evidence suggests that the stimulation of the medial olivocochlear efferent neurons causes similar alterations in cochlear frequency selectivity in adults and children.
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Affiliation(s)
- Srikanta K Mishra
- Department of Special Education/Communication Disorders, New Mexico State University, Las Cruces, New Mexico 88003-8001, USA
| | - Zoë Dinger
- Department of Special Education/Communication Disorders, New Mexico State University, Las Cruces, New Mexico 88003-8001, USA
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18
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Manley GA, van Dijk P. Frequency selectivity of the human cochlea: Suppression tuning of spontaneous otoacoustic emissions. Hear Res 2016; 336:53-62. [PMID: 27139323 DOI: 10.1016/j.heares.2016.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/25/2016] [Accepted: 04/15/2016] [Indexed: 11/16/2022]
Abstract
Frequency selectivity is a key functional property of the inner ear and since hearing research began, the frequency resolution of the human ear has been a central question. In contrast to animal studies, which permit invasive recording of neural activity, human studies must rely on indirect methods to determine hearing selectivity. Psychophysical studies, which used masking of a tone by other sounds, indicate a modest frequency selectivity in humans. By contrast, estimates using the phase delays of stimulus-frequency otoacoustic emissions (SFOAE) predict a remarkably high selectivity, unique among mammals. An alternative measure of cochlear frequency selectivity are suppression tuning curves of spontaneous otoacoustic emissions (SOAE). Several animal studies show that these measures are in excellent agreement with neural frequency selectivity. Here we contribute a large data set from normal-hearing young humans on suppression tuning curves (STC) of spontaneous otoacoustic emissions (SOAE). The frequency selectivities of human STC measured near threshold levels agree with the earlier, much lower, psychophysical estimates. They differ, however, from the typical patterns seen in animal auditory nerve data in that the selectivity is remarkably independent of frequency. In addition, SOAE are suppressed by higher-level tones in narrow frequency bands clearly above the main suppression frequencies. These narrow suppression bands suggest interactions between the suppressor tone and a cochlear standing wave corresponding to the SOAE frequency being suppressed. The data show that the relationship between pre-neural mechanical processing in the cochlea and neural coding at the hair-cell/auditory nerve synapse needs to be reconsidered.
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Affiliation(s)
- Geoffrey A Manley
- Cochlear and Auditory Brainstem Physiology, Department of Neuroscience, School of Medicine and Health Sciences, Cluster of Excellence "Hearing4all", Research Centre Neurosensory Science, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
| | - Pim van Dijk
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, P.O. Box 30.001, 9700 RB Groningen, The Netherlands; University of Groningen, Graduate School of Medical Sciences, Research School of Behavioural and Cognitive Neuroscience, The Netherlands.
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