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Manley GA, Maat B, Begall S, Malkemper P, Caspar KR, Moritz L, van Dijk P. Otoacoustic emissions in African mole-rats. Hear Res 2024; 445:108994. [PMID: 38520899 DOI: 10.1016/j.heares.2024.108994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/11/2024] [Accepted: 03/13/2024] [Indexed: 03/25/2024]
Abstract
African mole-rats display highly derived hearing that is characterized by low sensitivity and a narrow auditory range restricted to low frequencies < 10 kHz. Recently, it has been suggested that two species of these rodents do not exhibit distortion product otoacoustic emissions (DPOAE), which was interpreted as evidence for a lack of cochlear amplification. If true, this would make them unique among mammals. However, both theoretical considerations on the generation of DPOAE as well as previously published experimental evidence challenge this assumption. We measured DPOAE and stimulus-frequency otoacoustic emissions (SFOAE) in three species of African mole-rats (Ansell's mole-rat - Fukomys anselli; Mashona mole-rat - Fukomys darlingi; naked mole-rat - Heterocephalus glaber) and found unexceptional otoacoustic emission values. Measurements were complicated by the remarkably long, narrow and curved external ear canals of these animals, for which we provide a morphological description. Both DPOAE and SFOAE displayed the highest amplitudes near 1 kHz, which corresponds to the region of best hearing in all tested species, as well as to the frequency region of the low-frequency acoustic fovea previously described in Ansell's mole-rat. Thus, the cochlea in African mole-rats shares the ability to generate evoked otoacoustic emission with other mammals.
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Affiliation(s)
- Geoffrey A Manley
- Department of Neuroscience, Faculty of Medicine, and Cluster of Excellence "Hearing for All", University of Oldenburg, 26129 Oldenburg, Germany.
| | - Bert Maat
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, Groningen, The Netherlands
| | - Sabine Begall
- Department of General Zoology, University of Duisburg-Essen, Essen, Germany
| | - Pascal Malkemper
- Max Planck Research Group Neurobiology of Magnetoreception, Max Planck Institute for Neurobiology of Behavior - caesar, Bonn, Germany
| | - Kai R Caspar
- Department of General Zoology, University of Duisburg-Essen, Essen, Germany; Institute for Cell Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Leif Moritz
- Max Planck Research Group Neurobiology of Magnetoreception, Max Planck Institute for Neurobiology of Behavior - caesar, Bonn, Germany
| | - Pim van Dijk
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, Groningen, The Netherlands
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2
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Murakami Y, Fuji T. Difference between frequency and suppression tuning curves in a two-dimensional cochlear model. JASA EXPRESS LETTERS 2022; 2:094402. [PMID: 36182343 DOI: 10.1121/10.0013998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Suppression tuning curves (STCs) can be used to evaluate the cochlear frequency selectivity. However, the tip of the STC is located at a higher frequency than that of the frequency tuning curve (FTC) measured in the same preparation. Therefore, this study compares STCs from one-dimensional (1D) and two-dimensional (2D) cochlear models, which ignore and include short waves, respectively. The simulated STC tip is at a higher frequency than that of FTC in the 2D model, unlike the 1D model. The result suggests that short waves in the 2D model are responsible for the upward frequency of STC relative to FTC.
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Affiliation(s)
- Yasuki Murakami
- Faculty of Design, Kyushu University, 4-9-1 Shiobaru, Minamiku, Fukuoka 815-8540, Japan
| | - Takumi Fuji
- Graduate School of Life Science and System Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsuku, Kitakyushu, Fukuoka 808-0135, Japan ,
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3
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Engler S, Gaudrain E, de Kleine E, van Dijk P. Relationship between irregularities in spontaneous otoacoustic emissions suppression and psychophysical tuning curves. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 151:1055. [PMID: 35232113 DOI: 10.1121/10.0009278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
The suppression of spontaneous otoacoustic emissions (SOAEs) allows the objective evaluation of cochlear frequency selectivity by determining the suppression tuning curve (STC). Interestingly, some STCs have additional sidelobes at the high frequency flank, which are thought to result from interaction between the probe tone and the cochlear standing wave corresponding to the SOAE being suppressed. Sidelobes are often in regions of other neighboring SOAEs but can also occur in the absence of any other SOAE. The aim of this study was to compare STCs and psychoacoustic tuning curves (PTCs). Therefore, STCs and PTCs were measured in: (1) subjects in which the STC had a sidelobe, and (2) subjects without STC sidelobes. Additionally, PTCs were measured in subjects without SOAEs. Across participant groups, the quality factor Q10dB of the PTCs was similar, independently from whether SOAEs were present or absent. Thus, the presence of an SOAE does not provide enhanced frequency selectivity at the emission frequency. Moreover, both PTC and STC show irregularities, but these are not related in a straightforward way. This suggests that different mechanisms cause these irregularities.
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Affiliation(s)
- Sina Engler
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Hanzeplein 1, Groningen 9713 GZ, The Netherlands
| | - Etienne Gaudrain
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Hanzeplein 1, Groningen 9713 GZ, The Netherlands
| | - Emile de Kleine
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Hanzeplein 1, Groningen 9713 GZ, The Netherlands
| | - Pim van Dijk
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Hanzeplein 1, Groningen 9713 GZ, The Netherlands
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Gong Q, Liu Y, Xu R, Liang D, Peng Z, Yang H. Objective Assessment System for Hearing Prediction Based on Stimulus-Frequency Otoacoustic Emissions. Trends Hear 2021; 25:23312165211059628. [PMID: 34817273 PMCID: PMC8738859 DOI: 10.1177/23312165211059628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Stimulus-frequency otoacoustic emissions (SFOAEs) can be useful tools for assessing cochlear function noninvasively. However, there is a lack of reports describing their utility in predicting hearing capabilities. Data for model training were collected from 245 and 839 ears with normal hearing and sensorineural hearing loss, respectively. Based on SFOAEs, this study developed an objective assessment system consisting of three mutually independent modules, with the routine test module and the fast test module used for threshold prediction and the hearing screening module for identifying hearing loss. Results evaluated via cross-validation show that the routine test module and the fast test module predict hearing thresholds with similar performance from 0.5 to 8 kHz, with mean absolute errors of 7.06–11.61 dB for the routine module and of 7.40–12.60 dB for the fast module. However, the fast module involves less test time than is needed in the routine module. The hearing screening module identifies hearing status with a large area under the receiver operating characteristic curve (0.912–0.985), high accuracy (88.4–95.9%), and low false negative rate (2.9–7.0%) at 0.5–8 kHz. The three modules are further validated on unknown data, and the results are similar to those obtained through cross-validation, indicating these modules can be well generalized to new data. Both the routine module and fast module are potential tools for predicting hearing thresholds. However, their prediction performance in ears with hearing loss requires further improvement to facilitate their clinical utility. The hearing screening module shows promise as a clinical tool for identifying hearing loss.
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Affiliation(s)
- Qin Gong
- Department of Biomedical Engineering, 12442Tsinghua University, Beijing, China.,School of Medicine, Shanghai University, Shanghai, China
| | - Yin Liu
- Department of Biomedical Engineering, 12442Tsinghua University, Beijing, China
| | - Runyi Xu
- Department of Biomedical Engineering, 12442Tsinghua University, Beijing, China
| | - Dong Liang
- Department of Biomedical Engineering, 12442Tsinghua University, Beijing, China
| | - Zewen Peng
- Department of Biomedical Engineering, 12442Tsinghua University, Beijing, China
| | - Honghao Yang
- Department of Biomedical Engineering, 12442Tsinghua University, Beijing, China
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5
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Altoè A, Charaziak KK, Dewey JB, Moleti A, Sisto R, Oghalai JS, Shera CA. The Elusive Cochlear Filter: Wave Origin of Cochlear Cross-Frequency Masking. J Assoc Res Otolaryngol 2021; 22:623-640. [PMID: 34677710 DOI: 10.1007/s10162-021-00814-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 08/23/2021] [Indexed: 11/28/2022] Open
Abstract
The mammalian cochlea achieves its remarkable sensitivity, frequency selectivity, and dynamic range by spatially segregating the different frequency components of sound via nonlinear processes that remain only partially understood. As a consequence of the wave-based nature of cochlear processing, the different frequency components of complex sounds interact spatially and nonlinearly, mutually suppressing one another as they propagate. Because understanding nonlinear wave interactions and their effects on hearing appears to require mathematically complex or computationally intensive models, theories of hearing that do not deal specifically with cochlear mechanics have often neglected the spatial nature of suppression phenomena. Here we describe a simple framework consisting of a nonlinear traveling-wave model whose spatial response properties can be estimated from basilar-membrane (BM) transfer functions. Without invoking jazzy details of organ-of-Corti mechanics, the model accounts well for the peculiar frequency-dependence of suppression found in two-tone suppression experiments. In particular, our analysis shows that near the peak of the traveling wave, the amplitude of the BM response depends primarily on the nonlinear properties of the traveling wave in more basal (high-frequency) regions. The proposed framework provides perhaps the simplest representation of cochlear signal processing that accounts for the spatially distributed effects of nonlinear wave propagation. Shifting the perspective from local filters to non-local, spatially distributed processes not only elucidates the character of cochlear signal processing, but also has important consequences for interpreting psychophysical experiments.
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Affiliation(s)
- Alessandro Altoè
- Caruso Department of Otolaryngology Head & Neck Surgery, University of Southern California, CA, Los Angeles, USA.
| | - Karolina K Charaziak
- Caruso Department of Otolaryngology Head & Neck Surgery, University of Southern California, CA, Los Angeles, USA
| | - James B Dewey
- Caruso Department of Otolaryngology Head & Neck Surgery, University of Southern California, CA, Los Angeles, USA
| | - Arturo Moleti
- Department of Physics, University of Roma Tor Vergata, Rome, Italy
| | - Renata Sisto
- DIMEILA, INAIL, Monte Porzio Catone, Rome, Italy
| | - John S Oghalai
- Caruso Department of Otolaryngology Head & Neck Surgery, University of Southern California, CA, Los Angeles, USA
| | - Christopher A Shera
- Caruso Department of Otolaryngology Head & Neck Surgery, University of Southern California, CA, Los Angeles, USA.,Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, USA
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6
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Wilson US, Browning-Kamins J, Durante AS, Boothalingam S, Moleti A, Sisto R, Dhar S. Cochlear tuning estimates from level ratio functions of distortion product otoacoustic emissions. Int J Audiol 2021; 60:890-899. [PMID: 33612052 DOI: 10.1080/14992027.2021.1886352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Objective: Distortion product otoacoustic emission (DPOAE) levels plotted as a function of stimulus frequency ratio demonstrate a bandpass shape. This bandpass shape is narrower at higher frequencies compared to lower frequencies and thus has been thought to be related to cochlear mechanical tuning.Design: However, the frequency- and level-dependence of these functions above 8 kHz is largely unknown. Furthermore, how tuning estimates from these functions are related to behavioural tuning is not fully understood.Study Sample: From experiment 1, we report DPOAE level ratio functions (LRF) from seven normal-hearing, young-adults for f2 = 0.75-16 kHz and two stimulus levels of 62/52 and 52/37 dB FPL. We found that LRFs became narrower as a function of increasing frequency and decreasing level.Results: Tuning estimates from these functions increased as expected from 1-8 kHz. In experiment 2, we compared tuning estimates from DPOAE LRF to behavioural tuning in 24 normal-hearing, young adults for 1 and 4 kHz and found that behavioural tuning generally predicted DPOAE LRF estimated tuning.Conclusions: Our findings suggest that DPOAE LRFs generally reflect the tuning profile consistent with basilar membrane, neural, and behavioural tuning. However, further investigations are warranted to fully determine the use of DPOAE LRF as a clinical measure of cochlear tuning.
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Affiliation(s)
- Uzma Shaheen Wilson
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Evanston, IL, USA
| | - Jenna Browning-Kamins
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Evanston, IL, USA
| | | | | | - Arturo Moleti
- Physics Department, University of Roma Tor Vergata, Rome, Italy
| | | | - Sumitrajit Dhar
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Evanston, IL, USA.,Knowles Hearing Center, Northwestern University, Evanston, IL, USA
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7
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Liu Y, Xu R, Gong Q. Human Auditory-Frequency Tuning Is Sensitive to Tonal Language Experience. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2020; 63:4277-4288. [PMID: 33151817 DOI: 10.1044/2020_jslhr-20-00152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Purpose The aim of this study is to investigate whether human auditory frequency tuning can be influenced by tonal language experience. Method Perceptual tuning measured via psychophysical tuning curves and cochlear tuning derived via stimulus-frequency otoacoustic emission suppression tuning curves in 14 native speakers of a tonal language (Mandarin) were compared to those of 14 native speakers of a nontonal language (English) at 1 and 4 kHz. Results Group comparisons of both psychophysical tuning curves (p = .046) and stimulus-frequency otoacoustic emission suppression tuning curves (p = .007) in the 4-kHz region indicated sharper frequency tuning in the Mandarin-speaking group relative to the English-speaking group. The auditory tuning was better at the higher (4 kHz) than the lower (1 kHz) probe frequencies (p < .001). Conclusions The sharper auditory tuning in the 4-kHz cochlear region is associated with long-term tonal language (i.e., Mandarin) experience. Experience-dependent plasticity of tonal language may occur before the sound signal reaches central neural stages, as peripheral as the cochlea.
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Affiliation(s)
- Yin Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Runyi Xu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Qin Gong
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
- School of Medicine, Shanghai University, China
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8
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Cheatham MA. Comparing spontaneous and stimulus frequency otoacoustic emissions in mice with tectorial membrane defects. Hear Res 2020; 400:108143. [PMID: 33340968 DOI: 10.1016/j.heares.2020.108143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/20/2020] [Accepted: 12/02/2020] [Indexed: 01/28/2023]
Abstract
The global standing-wave model for generation of spontaneous otoacoustic emissions (SOAEs) suggests that they are amplitude-stabilized standing waves and that the spacing between SOAEs corresponds to the interval over which the phase changes by one cycle as determined from the phase-gradient delays of stimulus frequency otoacoustic emissions (SFOAEs). Because data characterizing the relationship between spontaneous and evoked emissions in nonhuman mammals are limited, we examined SOAEs and SFOAEs in tectorial membrane (TM) mutants and their controls. Computations indicate that the spacing between adjacent SOAEs is predicted by the SFOAE phase-gradient delays for TM mutants lacking Ceacam16, where SOAE frequencies are greater than ~20 kHz and the mutants retain near-normal hearing when young. Mice with a missense mutation in Tecta (TectaY1870C/+), as well as mice lacking Otoancorin (Otoa-/-), were also examined. Although these mutants exhibit hearing loss, they generate SOAEs with average frequencies of 11 kHz in TectaY1870C/+ and 6 kHz in Otoa-/-. In these animals, the spacing between adjacent SOAEs is larger than predicted by the SFOAE phase delays. It is also demonstrated that mice do not exhibit the strong frequency-dependence in signal coding that characterizes species with good low-frequency hearing. In fact, a transition occurs near the apical end of the mouse cochlea rather than at the mid-point along the cochlear partition. Hence, disagreements with the standing-wave model are not easily explained by a transition in tuning ratios between apical and basal regions of the cochlea, especially for SOAEs generated in TectaY1870C/+mice.
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Affiliation(s)
- Mary Ann Cheatham
- The Knowles Hearing Center, Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, 2-240 Frances Searle Building, 2240 Campus Drive, Evanston IL 60208, USA.
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9
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Wilson US, Browning-Kamins J, Boothalingam S, Moleti A, Sisto R, Dhar S. Relationship Between Behavioral and Stimulus Frequency Otoacoustic Emissions Delay-Based Tuning Estimates. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2020; 63:1958-1968. [PMID: 32464079 PMCID: PMC7839027 DOI: 10.1044/2020_jslhr-19-00386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/18/2020] [Accepted: 02/20/2020] [Indexed: 06/11/2023]
Abstract
Purpose The phase delay of stimulus frequency otoacoustic emissions (SFOAEs) has been proposed as a noninvasive, objective, and fast source for estimating cochlear mechanical tuning. However, the implementation of SFOAEs clinically has been thwarted by the gaps in understanding of the stability of SFOAE delay-based tuning estimates and their relationship to behavioral measures of tuning. Therefore, the goals of this study were (a) to investigate the relationship between delay-based tuning estimates from SFOAEs and simultaneously masked psychophysical tuning curves (PTCs) and (b) to assess the across- and within-session repeatability of tuning estimates from behavioral and OAE measures. Method Three sets of behavioral and OAE measurements were collected in 24 normal-hearing, young adults for two probe frequencies, 1 and 4 kHz. For each participant, delay-based tuning estimates were derived from the phase gradient of SFOAEs. SFOAE-based and behavioral estimates of tuning obtained using the fast-swept PTC paradigm were compared within and across sessions. Results In general, tuning estimates were sharper at 4 kHz compared to 1 kHz for both PTCs and SFOAEs. Statistical analyses revealed a significant correlation between SFOAE delay-based tuning and PTCs at 4 kHz, but not 1 kHz. Lastly, SFOAE delay-based tuning estimates showed better intra- and intersession repeatability compared to PTCs. Conclusions SFOAE phase-gradient delays reflect aspects of cochlear mechanical tuning, in that a frequency dependence similar to that of basilar membrane tuning was observed. Furthermore, the significant correlation with PTCs at 4 kHz and the high repeatability of SFOAE-based tuning measures offer promise of an objective, nonbehavioral assay of tuning in human ears.
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Affiliation(s)
- Uzma Shaheen Wilson
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Evanston, IL
| | - Jenna Browning-Kamins
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Evanston, IL
| | - Sriram Boothalingam
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Evanston, IL
- Waisman Center, University of Wisconsin-Madison, Madison, WI
| | - Arturo Moleti
- Physics Department, University of Roma Tor Vergata, Rome, Italy
| | - Renata Sisto
- Istituto Nazionale Assicurazione Infortuni sul Lavoro Research, Rome, Italy
| | - Sumitrajit Dhar
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Evanston, IL
- Knowles Hearing Center, Northwestern University, Evanston, IL
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10
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Vencovský V, Vetešník A, Gummer AW. Nonlinear reflection as a cause of the short-latency component in stimulus-frequency otoacoustic emissions simulated by the methods of compression and suppression. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:3992. [PMID: 32611132 DOI: 10.1121/10.0001394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
Stimulus-frequency otoacoustic emissions (SFOAEs) are generated by coherent reflection of forward traveling waves by perturbations along the basilar membrane. The strongest wavelets are backscattered near the place where the traveling wave reaches its maximal amplitude (tonotopic place). Therefore, the SFOAE group delay might be expected to be twice the group delay estimated in the cochlear filters. However, experimental data have yielded steady-state SFOAE components with near-zero latency. A cochlear model is used to show that short-latency SFOAE components can be generated due to nonlinear reflection of the compressor or suppressor tones used in SFOAE measurements. The simulations indicate that suppressors produce more pronounced short-latency components than compressors. The existence of nonlinear reflection components due to suppressors can also explain why SFOAEs can still be detected when suppressors are presented more than half an octave above the probe-tone frequency. Simulations of the SFOAE suppression tuning curves showed that phase changes in the SFOAE residual as the suppressor frequency increases are mostly determined by phase changes of the nonlinear reflection component.
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Affiliation(s)
- Václav Vencovský
- Department of Radioelectronics, Czech Technical University in Prague, Technická 2, 166 27 Prague, Czech Republic
| | - Aleš Vetešník
- Department of Nuclear Chemistry, Czech Technical University in Prague, Břehová 7, 115 19 Prague, Czech Republic
| | - Anthony W Gummer
- Department of Otolaryngology, Section of Physiological Acoustics and Communication, Eberhard-Karls-University Tübingen, Elfriede-Aulhorn-Strasse 5, 72076 Tübingen, Germany
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11
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Goodman SS, Lee C, Guinan JJ, Lichtenhan JT. The Spatial Origins of Cochlear Amplification Assessed by Stimulus-Frequency Otoacoustic Emissions. Biophys J 2020; 118:1183-1195. [PMID: 31968228 DOI: 10.1016/j.bpj.2019.12.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 12/04/2019] [Accepted: 12/27/2019] [Indexed: 10/25/2022] Open
Abstract
Cochlear amplification of basilar membrane traveling waves is thought to occur between a tone's characteristic frequency (CF) place and within one octave basal of the CF. Evidence for this view comes only from the cochlear base. Stimulus-frequency otoacoustic emissions (SFOAEs) provide a noninvasive alternative to direct measurements of cochlear motion that can be measured across a wide range of CF regions. Coherent reflection theory indicates that SFOAEs arise mostly from the peak region of the traveling wave, but several studies using far-basal suppressor tones claimed that SFOAE components originate many octaves basal of CF. We measured SFOAEs while perfusing guinea pig cochleas from apex to base with salicylate or KCl solutions that reduced outer-hair-cell function and SFOAE amplification. Solution effects on inner hair cells reduced auditory nerve compound action potentials (CAPs) and provided reference times for when solutions reached the SFOAE-frequency CF region. As solution flowed from apex to base, SFOAE reductions generally occurred later than CAP reductions and showed that the effects of cochlear amplification usually peaked ∼1/2 octave basal of the CF region. For tones ≥2 kHz, cochlear amplification typically extended ∼1.5 octaves basal of CF, and the data are consistent with coherent reflection theory. SFOAE amplification did not extend to the basal end of the cochlea, even though reticular lamina motion is amplified in this region, which indicates that reticular lamina motion is not directly coupled to basilar membrane traveling waves. Previous reports of SFOAE-frequency residuals produced by suppressor frequencies far above the SFOAE frequency are most likely due to additional sources created by the suppressor. For some tones <2 kHz, SFOAE amplification extended two octaves apical of CF, which highlights that different vibratory motions produce SFOAEs and CAPs, and that the amplification region depends on the cochlear mode of motion considered. The concept that there is a single "cochlear amplification region" needs to be revised.
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Affiliation(s)
- Shawn S Goodman
- Communication Sciences and Disorders, University of Iowa, Iowa City, Iowa
| | - Choongheon Lee
- Department of Otolaryngology, Washington University School of Medicine in St. Louis, St. Louis, Missouri
| | - John J Guinan
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts; Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, Massachusetts
| | - Jeffery T Lichtenhan
- Department of Otolaryngology, Washington University School of Medicine in St. Louis, St. Louis, Missouri.
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12
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Moore BCJ, Wan J, Varathanathan A, Naddell S, Baer T. No Effect of Musical Training on Frequency Selectivity Estimated Using Three Methods. Trends Hear 2019; 23:2331216519841980. [PMID: 31081487 DOI: 10.1177/2331216519841980] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
It is widely believed that the frequency selectivity of the auditory system is largely determined by processes occurring in the cochlea. If so, musical training would not be expected to influence frequency selectivity. Consistent with this, auditory filter shapes for low center frequencies do not differ for musicians and nonmusicians. However, it has been reported that psychophysical tuning curves (PTCs) at 4000 Hz were sharper for musicians than for nonmusicians. This study explored the origin of the discrepancy across studies. Frequency selectivity was estimated for musicians and nonmusicians using three methods: fast PTCs with a masker that swept in frequency, "traditional" PTCs obtained using several fixed masker center frequencies, and the notched-noise method. The signal frequency was 4000 Hz. The data were fitted assuming that each side of the auditory filter had the shape of a rounded-exponential function. The sharpness of the auditory filters, estimated as the Q10 values, did not differ significantly between musicians and nonmusicians for any of the methods, but detection efficiency tended to be higher for the musicians. This is consistent with the idea that musicianship influences auditory proficiency but does not influence the peripheral processes that determine the frequency selectivity of the auditory system.
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Affiliation(s)
| | - Jie Wan
- 1 Department of Psychology, University of Cambridge, UK.,2 Research School of Behavioural and Cognitive Neurosciences, University of Groningen, the Netherlands
| | | | | | - Thomas Baer
- 1 Department of Psychology, University of Cambridge, UK
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13
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Rasetshwane DM, Bosen EC, Kopun JG, Neely ST. Comparison of distortion-product otoacoustic emission and stimulus-frequency otoacoustic emission two-tone suppression in humans. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:4481. [PMID: 31893726 PMCID: PMC6930138 DOI: 10.1121/1.5139660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 06/10/2023]
Abstract
Distortion-product otoacoustic emission (DPOAE) and stimulus-frequency otoacoustic emission (SFOAE) are two types of acoustic signals emitted by the inner ear in response to tonal stimuli. The levels of both emission types may be reduced by the inclusion of additional (suppressor) tones with the stimulus. Comparison of two-tone suppression properties across emission type addresses a clinically relevant question of whether these two types of emission provide similar information about cochlear status. The purpose of this study was to compare DPOAE suppression to SFOAE suppression from the same ear in a group of participants with normal hearing. Probe frequency was approximately 1000 Hz, and the suppressor frequency varied from -1.5 to 0.5 octaves relative to the probe frequency. DPOAE and SFOAE suppression were compared in terms of (1) suppression growth rate (SGR), (2) superimposed suppression tuning curves (STCs), and (3) STC-derived metrics, such as high-frequency slope, cochlear amplifier gain, and QERB (ERB, equivalent rectangular bandwidth). Below the probe frequency, the SGR was slightly greater than one for SFOAEs and slightly less than two for DPOAEs. There were no differences in STC metrics across emission types. These observations may provide useful constraints on physiology-based models of otoacoustic emission suppression.
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Affiliation(s)
- Daniel M Rasetshwane
- Center for Hearing Research, Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA
| | - Emily C Bosen
- Center for Hearing Research, Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA
| | - Judy G Kopun
- Center for Hearing Research, Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA
| | - Stephen T Neely
- Center for Hearing Research, Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA
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Abstract
OBJECTIVES This study aims to determine the impact of controlling cochlear-source mechanism on the accuracy with which auditory status is identified using otoacoustic emissions (OAEs) in two groups of subjects with normal hearing (NH) and subjects with mild to moderate hearing loss. DESIGN Data were collected from 212 subjects with NH and with mild to moderate hearing loss who fell into two categories based on a distortion product OAE (DPOAE) screening protocol: the uncertain-identification group (where errors were likely) and the certain-identification group (where errors were unlikely). DPOAE fine-structure patterns were recorded at intervals surrounding f2 = 1, 2 and 4 kHz (f2/f1 ratio = 1.22), with L2 = 35, 45, and 55 dB SPL (L1/L2 ratio = 10 dB). The discrete cosine transform was used to smooth fine structure, limiting the source contribution to the distortion source only. Reflection-source OAEs were also recorded using amplitude-modulated stimulus frequency OAEs (AM-SFOAE). Area under the relative operating characteristic (AROC) curve was used to quantify test accuracy when the source contribution was controlled versus the condition where both sources contribute. Additionally, failure rate, fixed at 5% for NH ears, as a function of behavioral-threshold category was evaluated. RESULTS When data for the entire subject group were examined, reducing the reflection-source contribution to the DPOAE did not result in better test performance than the best control condition at any frequency tested. When the subjects with NH were restricted to those with confirmed fine structure, AROC analyses indicated that reducing the reflection-source contribution resulted in several small increases in the accuracy (2%-5%) with which auditory status was identified relative to the best control condition. This improvement was observed for the lowest stimulus levels (i.e., L2 = 35 or 45 dB SPL). In this subset of subjects, distortion-source DPOAEs resulted in more accurate identification of mild hearing loss for a fixed false-positive rate of 5% in NH ears at lower L2's, conditions with poor accuracy in the larger group of subjects. The impact of controlling the source contribution on the identification of moderate losses was less clear in the reduced subject group, with some conditions where the distortion-source DPOAE was more accurate than the control condition and other conditions where there was no change. There was no evidence that reflection-source AM-SFOAEs more accurately identified ears with hearing loss when compared to any of the DPOAE conditions in either the large or reduced group of subjects. CONCLUSION While improvements in test accuracy were observed for some subjects and some conditions (e.g., mild hearing losses and low stimulus levels in the reduced subset of subjects), these results suggest that restricting cochlear source contribution by "smoothing" DPOAE fine structure is not expected to improve DPOAE test accuracy in a general population of subjects. Likewise, recording reflection-source OAEs using the AM-SFOAE technique would not be expected to more accurately identify hearing status compared to mixed- or single-source DPOAEs.
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Cochlear, brainstem, and psychophysical responses show spectrotemporal tradeoff in human auditory processing. Neuroreport 2017; 28:17-22. [DOI: 10.1097/wnr.0000000000000714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Raufer S, Verhulst S. Otoacoustic emission estimates of human basilar membrane impulse response duration and cochlear filter tuning. Hear Res 2016; 342:150-160. [DOI: 10.1016/j.heares.2016.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 10/20/2016] [Accepted: 10/26/2016] [Indexed: 10/20/2022]
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Liu YW, Liu TC. Quasilinear reflection as a possible mechanism for suppressor-induced otoacoustic emission. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:4193. [PMID: 28040016 DOI: 10.1121/1.4968879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A frequency-domain iterative approach is developed to compute the change in characteristic impedance in the cochlea due to the presence of a suppressor tone. Based on this approach, a small transient wave passing by the best place (BP) of the suppressor is predicted to be partially reflected because of the suppressor-induced impedance variation. This computational approach is tested on a nonlinear model of cochlear mechanics [Liu, J. Acoust. Soc. Am. 136, 1788-1796 (2014)]. When a 9-kHz suppressor at 60 dB sound pressure level is delivered to the model, the characteristic impedance decreases by ∼20% near its BP. This localized impedance mismatch causes a forward-going wave at 4 kHz to reflect partially, and the magnitude of the reflected component is about -18 dB relative to the forward-going component near the stapes. The reflected components eventually emit from the cochlea to the ear canal, and the predicted amplitude of tone-burst evoked otoacoustic emissions (OAEs) agrees well with time-domain simulation. The present results suggest that, while the "suppressor" is meant to suppress the OAEs in experiments, its very presence might create an otherwise non-existing emission component via nonlinear scattering when its frequency is higher than that of the probe.
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Affiliation(s)
- Yi-Wen Liu
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Tzu-Chi Liu
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
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Manley GA. Comparative Auditory Neuroscience: Understanding the Evolution and Function of Ears. J Assoc Res Otolaryngol 2016; 18:1-24. [PMID: 27539715 DOI: 10.1007/s10162-016-0579-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/01/2016] [Indexed: 11/25/2022] Open
Abstract
Comparative auditory studies make it possible both to understand the origins of modern ears and the factors underlying the similarities and differences in their performance. After all lineages of land vertebrates had independently evolved tympanic middle ears in the early Mesozoic era, the subsequent tens of millions of years led to the hearing organ of lizards, birds, and mammals becoming larger and their upper frequency limits higher. In extant species, lizard papillae remained relatively small (<2 mm), but avian papillae attained a maximum length of 11 mm, with the highest frequencies in both groups near 12 kHz. Hearing-organ sizes in modern mammals vary more than tenfold, up to >70 mm (made possible by coiling), as do their upper frequency limits (from 12 to >200 kHz). The auditory organs of the three amniote groups differ characteristically in their cellular structure, but their hearing sensitivity and frequency selectivity within their respective hearing ranges hardly differ. In the immediate primate ancestors of humans, the cochlea became larger and lowered its upper frequency limit. Modern humans show an unusual trend in frequency selectivity as a function of frequency. It is conceivable that the frequency selectivity patterns in humans were influenced in their evolution by the development of speech.
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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, Carl von Ossietzky Strasse 9-11, 26129, Oldenburg, Germany.
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Moleti A, Sisto R. Estimating cochlear tuning dependence on stimulus level and frequency from the delay of otoacoustic emissions. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:945. [PMID: 27586727 DOI: 10.1121/1.4960588] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An objective technique based on the time-frequency analysis of otoacoustic emissions is proposed to get fast and stable estimates of cochlear tuning. Time-frequency analysis allows one to get stable measurements of the delay/frequency function, which is theoretically expected to be a function of cochlear tuning. Theoretical considerations and numerical solutions of a nonlinear cochlear model suggest that the average phase-gradient delay of the otoacoustic emission single-reflection components, weighted, for each frequency, by the amplitude of the corresponding wavelet coefficients, approximately scales as the square root of the cochlear quality factor. The application of the method to human stimulus-frequency and transient-evoked otoacoustic emissions shows that tuning decreases approximately by a factor of 2, as the stimulus level increases by 30 dB in a moderate stimulus level range. The results also show a steady increase of tuning with increasing frequency, by a factor of 2 between 1 and 5 kHz. This last result is model-dependent, because it relies on the assumption that cochlear scale-invariance breaking is only due to the frequency dependence of tuning. The application of the method to the reflection component of distortion product otoacoustic emissions, separated using time-frequency filtering, is complicated by the necessity of effectively canceling the distortion component.
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Affiliation(s)
- Arturo Moleti
- Physics Department, University of Roma Tor Vergata, Via della Ricerca Scientifica, 1, 00133 Roma, Italy
| | - Renata Sisto
- Italian Workers Compensation Authority (INAIL) Research, Via di Fontana Candida, 1, 00044 Monteporzio Catone (RM), Italy
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Wang Y, Gong Q, Zhang T. The influence of probe level on the tuning of stimulus frequency otoacoustic emissions and behavioral test in human. Biomed Eng Online 2016; 15:51. [PMID: 27160830 PMCID: PMC4862048 DOI: 10.1186/s12938-016-0167-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/28/2016] [Indexed: 12/03/2022] Open
Abstract
Background Frequency selectivity (FS) of the auditory system is established at the level of the cochlea and it is important for the perception of complex sounds. Although direct measurements of cochlear FS require surgical preparation, it can also be estimated with the measurements of otoacoustic emissions or behavioral tests, including stimulus frequency otoacoustic emission suppression tuning curves (SFOAE STCs) or psychophysical tuning curves (PTCs). These two methods result in similar estimates of FS at low probe levels. As the compressive nonlinearity of cochlea is strongly dependent on the stimulus intensity, the sharpness of tuning curves which is relevant to the cochlear nonlinearity will change as a function of probe level. The present study aims to investigate the influence of different probe levels on the relationship between SFOAE STCs and PTCs. Methods The study included 15 young subjects with normal hearing. SFOAE STCs and PTCs were recorded at low and moderate probe levels for frequencies centred at 1, 2, and 4 kHz. The ratio or the difference of the characteristic parameters between the two methods was calculated at each probe level. The effect of probe level on the ratio or the difference between the parameters of SFOAE STCs and PTCs was then statistically analysed. Results The tuning of SFOAE STCs was significantly positively correlated with the tuning of the PTCs at both low and moderate probe levels; yet, at the moderate probe level, the SFOAE STCs were consistently broader than the PTCs. The mean ratio of sharpness of tuning at low probe levels was constantly around 1 while around 1.5 at moderate probe levels. Conclusions Probe level had a significant effect on the sharpness of tuning between the two methods of estimating FS. SFOAE STC seems a good alternative measurement of PTC for FS assessment at low probe levels. At moderate probe levels, SFOAE STC and PTC were not equivalent measures of the FS in terms of their bandwidths. Because SFOAE STCs are not biased by higher levels auditory processing, they may represent cochlear FS better than PTCs.
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Affiliation(s)
- Yao Wang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084, China
| | - Qin Gong
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084, China. .,Research Center of Biomedical Engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
| | - Tao Zhang
- Tsinghua National Laboratory for Information Science and Technology (TNList), Tsinghua University, Beijing, 100084, China
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Bidelman GM, Nelms C, Bhagat SP. Musical experience sharpens human cochlear tuning. Hear Res 2016; 335:40-46. [DOI: 10.1016/j.heares.2016.02.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/06/2016] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
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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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Berezina-Greene MA, Guinan JJ. Stimulus Frequency Otoacoustic Emission Delays and Generating Mechanisms in Guinea Pigs, Chinchillas, and Simulations. J Assoc Res Otolaryngol 2015; 16:679-94. [PMID: 26373935 DOI: 10.1007/s10162-015-0543-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 08/30/2015] [Indexed: 11/30/2022] Open
Abstract
According to coherent reflection theory (CRT), stimulus frequency otoacoustic emissions (SFOAEs) arise from cochlear irregularities coherently reflecting energy from basilar membrane motion within the traveling-wave peak. This reflected energy arrives in the ear canal predominantly with a single delay at each frequency. However, data from humans and animals indicate that (1) SFOAEs can have multiple delay components, (2) low-frequency SFOAE delays are too short to be accounted for by CRT, and (3) "SFOAEs" obtained with a 2nd ("suppressor") tone ≥2 octaves above the probe tone have been interpreted as arising from the area basal to the region of cochlear amplification. To explore these issues, we collected SFOAEs by the suppression method in guinea pigs and time-frequency analyzed these data, simulated SFOAEs, and published chinchilla SFOAEs. Time-frequency analysis revealed that most frequencies showed only one SFOAE delay component while other frequencies had multiple components including some with short delays. We found no systematic patterns in the occurrence of multiple delay components. Using a cochlear model that had significant basilar membrane motion only in the peak region of the traveling wave, simulated SFOAEs had single and multiple delay components similar to the animal SFOAEs. This result indicates that multiple components (including ones with short delays) can originate from cochlear mechanical irregularities in the SFOAE peak region and are not necessarily indicative of SFOAE sources in regions ≥2 octaves basal of the SFOAE peak region. We conclude that SFOAEs obtained with suppressors close to the probe frequency provide information primarily about the mechanical response in the region that receives amplification, and we attribute the too-short SFOAE delays at low frequencies to distortion-source SFOAEs and coherent reflection from multiple cochlear motions. Our findings suggest that CRT needs revision to include reflections from multiple motions in the cochlear apex.
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Affiliation(s)
- Maria A Berezina-Greene
- Eaton-Peabody Lab, Mass. Eye and Ear Infirmary, 243 Charles St, Boston, MA, 02114, USA. .,Harvard-MIT HST Speech and Hearing Bioscience and Technology Program, Cambridge, MA, USA.
| | - John J Guinan
- Eaton-Peabody Lab, Mass. Eye and Ear Infirmary, 243 Charles St, Boston, MA, 02114, USA. .,Harvard-MIT HST Speech and Hearing Bioscience and Technology Program, Cambridge, MA, USA. .,Harvard Medical School, Boston, MA, USA.
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Charaziak KK, Siegel JH. Tuning of SFOAEs Evoked by Low-Frequency Tones Is Not Compatible with Localized Emission Generation. J Assoc Res Otolaryngol 2015; 16:317-29. [PMID: 25813430 PMCID: PMC4417092 DOI: 10.1007/s10162-015-0513-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 02/17/2015] [Indexed: 12/20/2022] Open
Abstract
Stimulus-frequency otoacoustic emissions (SFOAEs) appear to be well suited for assessing frequency selectivity because, at least on theoretical grounds, they originate over a restricted region of the cochlea near the characteristic place of the evoking tone. In support of this view, we previously found good agreement between SFOAE suppression tuning curves (SF-STCs) and a control measure of frequency selectivity (compound action potential suppression tuning curves (CAP-STC)) for frequencies above 3 kHz in chinchillas. For lower frequencies, however, SF-STCs and were over five times broader than the CAP-STCs and demonstrated more high-pass rather than narrow band-pass filter characteristics. Here, we test the hypothesis that the broad tuning of low-frequency SF-STCs is because emissions originate over a broad region of the cochlea extending basal to the characteristic place of the evoking tone. We removed contributions of the hypothesized basally located SFOAE sources by either pre-suppressing them with a high-frequency interference tone (IT; 4.2, 6.2, or 9.2 kHz at 75 dB sound pressure level (SPL)) or by inducing acoustic trauma at high frequencies (exposures to 8, 5, and lastly 3-kHz tones at 110-115 dB SPL). The 1-kHz SF-STCs and CAP-STCs were measured for baseline, IT present and following the acoustic trauma conditions in anesthetized chinchillas. The IT and acoustic trauma affected SF-STCs in an almost indistinguishable way. The SF-STCs changed progressively from a broad high-pass to narrow band-pass shape as the frequency of the IT was lowered and for subsequent exposures to lower-frequency tones. Both results were in agreement with the "basal sources" hypothesis. In contrast, CAP-STCs were not changed by either manipulation, indicating that neither the IT nor acoustic trauma affected the 1-kHz characteristic place. Thus, unlike CAPs, SFOAEs cannot be considered as a place-specific measure of cochlear function at low frequencies, at least in chinchillas.
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Affiliation(s)
- Karolina K Charaziak
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, USA,
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Christensen AT, Ordoñez R, Hammershøi D. Stimulus ratio dependence of low-frequency distortion-product otoacoustic emissions in humans. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:679-689. [PMID: 25698003 DOI: 10.1121/1.4906157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Active amplifiers within the cochlea generate, as a by-product of their function, distortion-product otoacoustic emissions (DPOAEs) in response to specific two-tone stimuli. Focus has been on invoking emissions in a mid-frequency range from ∼0.5 to 4 kHz. The present study investigates stimulus parameters of the DPOAE at 2f1-f2 frequencies below 0.5 kHz. Eighteen out of 21 young human adults screened had audiometrically normal hearing for inclusion in the experiment. DPOAEs were measured with pure-tone stimuli in four configurations: f2 fixed around 2.13 kHz, f2 fixed around 0.53 kHz, 2f1-f2 fixed at 1.23 kHz and 0.25 kHz. Eight stimulus ratios, f2/f1, and three stimulus sound pressure levels, L1/L2, were measured in each configuration. Trends in ratio-magnitude responses for the mid-frequency DPOAE agree with those reported in previous literature. DPOAEs are not limited to distortion frequencies >0.5 kHz, but the stimulus ratio invoking the largest DPOAE in the mid-frequency range does not do so in the low-frequency range. Guiding the ratio according to the equivalent rectangular bandwidth of auditory filters maintains the DPOAE level.
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Affiliation(s)
- Anders T Christensen
- Acoustics, Department of Electronic Systems, Aalborg University, Aalborg, Denmark
| | - Rodrigo Ordoñez
- Acoustics, Department of Electronic Systems, Aalborg University, Aalborg, Denmark
| | - Dorte Hammershøi
- Acoustics, Department of Electronic Systems, Aalborg University, Aalborg, Denmark
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Gong Q, Wang Y, Xian M. An objective assessment method for frequency selectivity of the human auditory system. Biomed Eng Online 2014; 13:171. [PMID: 25522838 PMCID: PMC4290461 DOI: 10.1186/1475-925x-13-171] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 12/05/2014] [Indexed: 11/18/2022] Open
Abstract
Background Frequency selectivity (FS) is an important aspect of auditory function, and is typically described by a tuning curve function. Sharply tuned curves represent a higher acuity in detecting frequency differences, and conversely, broadly tuned curves demonstrate a lower acuity. One way of obtaining tuning curves is from techniques based on subjective behavioral responses, which yields psychophysical tuning curves (PTCs). In contrast, other methods rely on objective auditory responses to sound, such as neuron responses and otoacoustic emissions, amongst others. The present study introduces an objective method that uses stimulus frequency otoacoustic emissions (SFOAEs) to assemble suppression tuning curves (STCs). Finding an objective method of accurately measuring human FS is very important, as it would permit the FS to be assayed in non-responsive patients (e.g., neonates or comatose patients). However, before the objective method can be applied, it must be demonstrated that its ability to estimate the FS, gives comparable results to those obtained by subjective procedures i.e. PTCs. Methods SFOAEs responses, generated in the peripheral auditory system, were used to produce STCs. PTCs were measured by behavioral responses. The validity of the objective measures of human FS were determined by comparing stimulus frequency otoacoustic emission suppression tuning curves (SFOAE STCs) to PTCs at common stimulus parameters in 10 individuals with normal hearing, at low probe-tone levels. Results The average Q10 ratios measured between PTCs and SFOAE STCs from subjects were close to 1 at various center frequencies (F2,24 = .15, p = .858). The estimates of FS provided by SFOAE STCs and PTCs were similar. Conclusions This system could be used to estimate auditory FS by both objective and subjective methods. SFOAE STCs have the potential to provide an objective estimate of auditory FS.
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Affiliation(s)
- Qin Gong
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China.
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Wojtczak M, Beim JA, Oxenham AJ. Exploring the role of feedback-based auditory reflexes in forward masking by schroeder-phase complexes. J Assoc Res Otolaryngol 2014; 16:81-99. [PMID: 25338224 DOI: 10.1007/s10162-014-0495-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 10/02/2014] [Indexed: 10/24/2022] Open
Abstract
Several studies have postulated that psychoacoustic measures of auditory perception are influenced by efferent-induced changes in cochlear responses, but these postulations have generally remained untested. This study measured the effect of stimulus phase curvature and temporal envelope modulation on the medial olivocochlear reflex (MOCR) and on the middle-ear muscle reflex (MEMR). The role of the MOCR was tested by measuring changes in the ear-canal pressure at 6 kHz in the presence and absence of a band-limited harmonic complex tone with various phase curvatures, centered either at (on-frequency) or well below (off-frequency) the 6-kHz probe frequency. The influence of possible MEMR effects was examined by measuring phase-gradient functions for the elicitor effects and by measuring changes in the ear-canal pressure with a continuous suppressor of the 6-kHz probe. Both on- and off-frequency complex tone elicitors produced significant changes in ear canal sound pressure. However, the pattern of results was not consistent with the earlier hypotheses postulating that efferent effects produce the psychoacoustic dependence of forward-masked thresholds on masker phase curvature. The results also reveal unexpectedly long time constants associated with some efferent effects, the source of which remains unknown.
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Affiliation(s)
- Magdalena Wojtczak
- Department of Psychology, University of Minnesota, N218 Elliott Hall, 75 East River Rd., Minneapolis, MN, 55455, USA,
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Lewis JD, Goodman SS. Basal contributions to short-latency transient-evoked otoacoustic emission components. J Assoc Res Otolaryngol 2014; 16:29-45. [PMID: 25303881 DOI: 10.1007/s10162-014-0493-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 09/24/2014] [Indexed: 10/24/2022] Open
Abstract
The presence of short-latency (SL), less compressive-growing components in bandpass-filtered transient-evoked otoacoustic emission (TEOAE) waveforms may implicate contributions from cochlear regions basal to the tonotopic place. Recent empirical work suggests a region of SL generation between ∼1/5 and 1/10-octave basal to the TEOAE frequency's tonotopic place. However, this estimate may be biased to regions closer to the tonotopic place as the TEOAE extraction technique precluded measurement of components with latencies shorter than ∼5 ms. Using a variant of the non-linear, double-evoked extraction paradigm that permitted extraction of components with latencies as early as 1 ms, the current study empirically estimated the spatial-extent of the cochlear region contributing to 2 kHz SL TEOAE components. TEOAEs were evoked during simultaneous presentation of a suppressor stimulus, in order to suppress contributions to the TEOAE from different places along the cochlear partition. Three or four different-latency components of similar frequency content (∼2 kHz) were identified for most subjects. Component latencies ranged from 1.4 to 9.6 ms; latency was predictive of the component's growth rate and the suppressor frequency to which the component's magnitude was most sensitive to change. As component latency decreased, growth became less compressive and suppressor-frequency sensitivity shifted to higher frequencies. The shortest-latency components were most sensitive to suppressors approximately 3/5-octave higher than their nominal frequency of 2 kHz. These results are consistent with a distributed region of generation extending to approximately 3/5-octave basal to the TEOAE frequency's tonotopic place. The empirical estimates of TEOAE generation are similar to model-based estimates where generation of the different-latency components occurs through linear reflection from impedance discontinuities distributed across the cochlear partition.
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Affiliation(s)
- James D Lewis
- Boys Town National Research Hospital, 555 North 30th Street, Omaha, NE, 68131, USA,
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Charaziak KK, Souza PE, Siegel JH. Exploration of stimulus-frequency otoacoustic emission suppression tuning in hearing-impaired listeners. Int J Audiol 2014; 54:96-105. [PMID: 25290042 DOI: 10.3109/14992027.2014.941074] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Otoacoustic emissions (OAEs) can provide useful measures of tuning of auditory filters. We previously established that stimulus-frequency (SF) OAE suppression tuning curves (STCs) reflect major features of behavioral tuning (psychophysical tuning curves, PTCs) in normally-hearing listeners. Here, we aim to evaluate whether SFOAE STCs reflect changes in PTC tuning in cases of abnormal hearing. DESIGN PTCs and SFOAE STCs were obtained at 1 kHz and/or 4 kHz probe frequencies. For exploratory purposes, we collected SFOAEs measured across a wide frequency range and contrasted them to commonly measured distortion product (DP) OAEs. STUDY SAMPLE Thirteen listeners with varying degrees of sensorineural hearing loss. RESULTS Except for a few listeners with the most hearing loss, the listeners had normal/nearly normal PTCs. However, attempts to record SFOAE STCs in hearing-impaired listeners were challenging and sometimes unsuccessful due to the high level of noise at the SFOAE frequency, which is not a factor for DPOAEs. In cases of successful measurements of SFOAE STCs there was a large variability in agreement between SFOAE STC and PTC tuning. CONCLUSIONS These results indicate that SFOAE STCs cannot substitute for PTCs in cases of abnormal hearing, at least with the paradigm adopted in this study.
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Affiliation(s)
- Karolina K Charaziak
- The Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, School of Communication, Northwestern University , Evanston , USA
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Charaziak KK, Siegel JH. Estimating cochlear frequency selectivity with stimulus-frequency otoacoustic emissions in chinchillas. J Assoc Res Otolaryngol 2014; 15:883-96. [PMID: 25230801 DOI: 10.1007/s10162-014-0487-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 09/03/2014] [Indexed: 11/29/2022] Open
Abstract
It has been suggested that the tuning of the cochlear filters can be derived from measures of otoacoustic emissions (OAEs). Two approaches have been proposed to estimate cochlear frequency selectivity using OAEs evoked with a single tone (stimulus-frequency (SF)) OAEs: based on SFOAE group delays (SF-GDs) and on SFOAE suppression tuning curves (SF-STCs). The aim of this study was to evaluate whether either SF-GDs or SF-STCs obtained with low probe levels (30 dB SPL) correlate with more direct measures of cochlear tuning (compound action potential suppression tuning curves (CAP-STCs)) in chinchillas. The SFOAE-based estimates of tuning covaried with CAP-STCs tuning for >3 kHz probe frequencies, indicating that these measures are related to cochlear frequency selectivity. However, the relationship may be too weak to predict tuning with either SFOAE method in an individual. The SF-GD prediction of tuning was sharper than CAP-STC tuning. On the other hand, SF-STCs were consistently broader than CAP-STCs implying that SFOAEs may have less restricted region of generation in the cochlea than CAPs. Inclusion of <3 kHz data in a statistical model resulted in no significant or borderline significant covariation among the three methods: neither SFOAE test appears to reliably estimate an individual's CAP-STC tuning at low-frequencies. At the group level, SF-GDs and CAP-STCs showed similar tuning at low frequencies, while SF-STCs were over five times broader than the CAP-STCs indicating that low-frequency SFOAE may originate over a very broad region of the cochlea extending ≥5 mm basal to the tonotopic place of the probe.
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Affiliation(s)
- Karolina K Charaziak
- Department of Communication Sciences and Disorders, School of Communication, Northwestern University, 2240 Campus Drive, Evanston, IL, 60208-2952, USA,
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