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Peacock J, Spellman GM, Field DJ, Mason MJ, Mayr G. Comparative morphology of the avian bony columella. Anat Rec (Hoboken) 2024; 307:1735-1763. [PMID: 37365751 DOI: 10.1002/ar.25278] [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: 02/16/2023] [Revised: 06/01/2023] [Accepted: 06/04/2023] [Indexed: 06/28/2023]
Abstract
In birds, the columella is the only bony element of the sound conducting apparatus, conveying vibrations of the cartilaginous extracolumella to the fluid of the inner ear. Although avian columellar morphology has attracted some attention over the past century, it nonetheless remains poorly described in the literature. The few existing studies mostly focus on morphological descriptions in relatively few taxa, with no taxonomically broad surveys yet published. Here we use observations of columellae from 401 extant bird species to provide a comprehensive survey of columellar morphology in a phylogenetic context. We describe the columellae of several taxa for the first time and identify derived morphologies characterizing higher-level clades based on current phylogenies. In particular, we identify a derived columellar morphology diagnosing a major subclade of Accipitridae. Within Suliformes, we find that Fregatidae, Sulidae, and Phalacrocoracidae share a derived morphology that is absent in Anhingidae, suggesting a secondary reversal. Phylogenetically informed comparisons allow recognition of instances of homoplasy, including the distinctive bulbous columellae in suboscine passerines and taxa belonging to Eucavitaves, and bulging footplates that appear to have evolved at least twice independently in Strigiformes. We consider phylogenetic and functional factors influencing avian columellar morphology, finding that aquatic birds possess small footplates relative to columellar length, possibly related to hearing function in aquatic habitats. By contrast, the functional significance of the distinctive bulbous basal ends of the columellae of certain arboreal landbird taxa remains elusive.
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Affiliation(s)
- John Peacock
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Garth M Spellman
- Department of Zoology, Denver Museum of Nature and Science, Denver, Colorado, USA
| | - Daniel J Field
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
- Museum of Zoology, University of Cambridge, Cambridge, UK
| | - Matthew J Mason
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Gerald Mayr
- Ornithological Section, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
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2
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Bowers P, Ravicz ME, Rosowski JJ. Measurements of bone-conducted sound in the chinchilla external ear. Hear Res 2024; 441:108926. [PMID: 38096706 PMCID: PMC10767666 DOI: 10.1016/j.heares.2023.108926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/20/2023] [Accepted: 12/03/2023] [Indexed: 12/27/2023]
Abstract
We measure bone-conduction (BC) induced skull velocity, sound pressure at the tympanic membrane (TM) and inner-ear compound-action potentials (CAP) before and after manipulating the ear canal, ossicles, and the jaw to investigate the generation of BC induced ear-canal sound pressures and their contribution to inner-ear BC response in the ears of chinchillas. These measurements suggest that in chinchilla: i.) Vibrations of the bony ear canal walls contribute significantly to BC-induced ear canal sound pressures, as occluding the ear canal at the bone-cartilaginous border causes a 10 dB increase in sound pressure at the TM (PTM) at frequencies below 2 kHz. ii.) The contributions to PTM of ossicular and TM motions when driven in reverse by BC-induced inner-ear sound pressures are small. iii.) The contribution of relative motions of the jaw and ear canal to PTM is small. iv.) Comparison of the effect of canal occlusion on PTM and CAP thresholds point out that BC-induced ear canal sound pressures contribute significantly to bone-conduction stimulation of the inner ear when the ear canal is occluded.
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Affiliation(s)
- Peter Bowers
- Speech and Hearing Bioscience and Technology Program, Harvard Graduate School of Arts and Sciences, Cambridge MA, United States
| | - Michael E Ravicz
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston MA, United States
| | - John J Rosowski
- Speech and Hearing Bioscience and Technology Program, Harvard Graduate School of Arts and Sciences, Cambridge MA, United States; Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston MA, United States; Department of Otolaryngology and Head & Neck Surgery, Harvard Medical School, Boston MA, United States.
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3
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Wils I, Geerardyn A, Putzeys T, Denis K, Verhaert N. Lumped element models of sound conduction in the human ear: A systematic review. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:1696-1709. [PMID: 37712750 DOI: 10.1121/10.0020841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 08/16/2023] [Indexed: 09/16/2023]
Abstract
Lumped element models facilitate investigating the fundamental mechanisms of human ear sound conduction. This systematic review aims to guide researchers to the optimal model for the investigated parameters. For this purpose, the literature was reviewed up to 12 July 2023, according to the PRISMA guidelines. Seven models are included via database searching, and another 19 via cross-referencing. The quality of the models is assessed by comparing the predicted middle ear transfer function, the tympanic membrane impedance, the energy reflectance, and the intracochlear pressures (ICPs) (scala vestibuli, scala tympani, and differential) with experimental data. Regarding air conduction (AC), the models characterize the pathway from the outer to the inner ear and accurately predict all six aforementioned parameters. This contrasts with the few existing bone conduction (BC) models that simulate only a part of the ear. In addition, these models excel at predicting one observable parameter, namely, ICP. Thus, a model that simulates BC from the coupling site to the inner ear is still lacking and would increase insights into the human ear sound conduction. Last, this review provides insights and recommendations to determine the appropriate model for AC and BC implants, which is highly relevant for future clinical applications.
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Affiliation(s)
- Irina Wils
- Department of Neurosciences, KU Leuven, B-3000 Leuven, Belgium
| | | | - Tristan Putzeys
- Department of Neurosciences, KU Leuven, B-3000 Leuven, Belgium
| | - Kathleen Denis
- Department of Mechanical Engineering, KU Leuven, B-3000 Leuven, Belgium
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4
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Remenschneider AK, Cheng JT, Herrmann BS, Rosowski JJ. Characterization and Clinical Use of Bone Conduction Transducers at Extended High Frequencies. Hear Res 2023; 429:108688. [PMID: 36628803 PMCID: PMC9953386 DOI: 10.1016/j.heares.2022.108688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/21/2022] [Accepted: 12/27/2022] [Indexed: 01/01/2023]
Abstract
Measurement of bone conduction (BC) hearing thresholds at extended high frequencies (EHF; above 8 kHz) is of clinical interest but is technically complicated by limitations in standard BC transducer output, a lack of calibration standards and sparse clinical data from human subjects. A recently described calibration scheme using an artificial mastoid and interposed accelerometer is applied in this study to characterize and compare acceleration and computed force outputs over the 4-20 kHz range of two standard BC transducers: the RadioEar® B71 and B81, as well as two non-standard, commercially available BC transducers: the Tascam® HP-F200 and the Aftershokz® AS400. Measures of linear output growth, harmonic distortion and acoustic radiation are assessed and compared across devices. A maximum linear input voltage is established for each BC transducer using measurements of linear output growth and total harmonic distortion. At maximum linear input level, the Tascam shows superior force output by 25 to 40 dB above 8 kHz and the widest dynamic EHF range. Acoustic radiation per output force was lowest for the Tascam, whereas the AS400 behaved more like an air conduction earphone than a force generator. In a cohort of 15 normal hearing volunteers, BC thresholds, measured with the Tascam and reported in dB re 1 rms μN, were consistent with historical measures of EHF BC thresholds in similar subjects using an alternative BC transducer.
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Affiliation(s)
- Aaron K Remenschneider
- Department of Otolaryngology, Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA; Department of Otolaryngology, UMass Memorial Medical Center, UMass Chan Medical School, Worcester, MA 01655, USA.
| | - Jeffrey Tao Cheng
- Department of Otolaryngology, Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - Barbara S Herrmann
- Department of Otolaryngology, Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - John J Rosowski
- Department of Otolaryngology, Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
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5
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Ugarteburu M, Withnell RH, Cardoso L, Carriero A, Richter CP. Mammalian middle ear mechanics: A review. Front Bioeng Biotechnol 2022; 10:983510. [PMID: 36299283 PMCID: PMC9589510 DOI: 10.3389/fbioe.2022.983510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
The middle ear is part of the ear in all terrestrial vertebrates. It provides an interface between two media, air and fluid. How does it work? In mammals, the middle ear is traditionally described as increasing gain due to Helmholtz's hydraulic analogy and the lever action of the malleus-incus complex: in effect, an impedance transformer. The conical shape of the eardrum and a frequency-dependent synovial joint function for the ossicles suggest a greater complexity of function than the traditional view. Here we review acoustico-mechanical measurements of middle ear function and the development of middle ear models based on these measurements. We observe that an impedance-matching mechanism (reducing reflection) rather than an impedance transformer (providing gain) best explains experimental findings. We conclude by considering some outstanding questions about middle ear function, recognizing that we are still learning how the middle ear works.
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Affiliation(s)
- Maialen Ugarteburu
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
| | - Robert H. Withnell
- Department of Speech, Language and Hearing Sciences, Indiana University, Bloomington, IN, United States
| | - Luis Cardoso
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
| | - Alessandra Carriero
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
| | - Claus-Peter Richter
- Department of Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States
- Department of Communication Sciences and Disorders, Northwestern University, Chicago, IL, United States
- The Hugh Knowles Center, Northwestern University, Chicago, IL, United States
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Liang J, Ke Z, Welch PV, Gan RZ, Dai C. A comprehensive finite element model for studying Cochlear-Vestibular interaction. Comput Methods Biomech Biomed Engin 2021; 25:204-214. [PMID: 34641759 DOI: 10.1080/10255842.2021.1946522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We present a 3-D finite element (FE) model of the chinchilla's inner ear consisting of the entire cochlea structure and the vestibular system. The reaction of the basilar membrane to the head rotation and the reaction of ampulla to the stapes movement were investigated. These results demonstrate the existence of hearing-vestibular system interaction. They provide an explanation to the clinical finding on the coexistence between hearing loss and equilibration dysfunction. It is a preliminary, yet critical step toward the development of a comprehensive FE model of an entire ear for mechano-acoustic analysis.
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Affiliation(s)
- Junfeng Liang
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Zhang Ke
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Paige V Welch
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Rong Z Gan
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Chenkai Dai
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
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7
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Lin X, Meenderink SWF, Stomackin G, Jung TT, Martin GK, Dong W. Forward and Reverse Middle Ear Transmission in Gerbil with a Normal or Spontaneously Healed Tympanic Membrane. J Assoc Res Otolaryngol 2021; 22:261-274. [PMID: 33591494 DOI: 10.1007/s10162-020-00779-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/19/2020] [Indexed: 11/25/2022] Open
Abstract
Tympanic membranes (TM) that have healed spontaneously after perforation present abnormalities in their structural and mechanical properties; i.e., they are thickened and abnormally dense. These changes result in a deterioration of middle ear (ME) sound transmission, which is clinically presented as a conductive hearing loss (CHL). To fully understand the ME sound transmission under TM pathological conditions, we created a gerbil model with a controlled 50% pars tensa perforation, which was left to heal spontaneously for up to 4 weeks (TM perforations had fully sealed after 2 weeks). After the recovery period, the ME sound transmission, both in the forward and reverse directions, was directly measured with two-tone stimulation. Measurements were performed at the input, the ossicular chain, and output of the ME system, i.e., at the TM, umbo, and scala vestibuli (SV) next to the stapes. We found that variations in ME transmission in forward and reverse directions were not symmetric. In the forward direction, the ME pressure gain decreased in a frequency-dependent manner, with smaller loss (within 10 dB) at low frequencies and more dramatic loss at high frequency regions. The loss pattern was mainly from the less efficient acoustical to mechanical coupling between the TM and umbo, with little changes along the ossicular chain. In the reverse direction, the variations in these ears are relatively smaller. Our results provide detailed functional observations that explain CHL seen in clinical patients with abnormal TM, e.g., caused by otitis media, that have healed spontaneously after perforation or post-tympanoplasty, especially at high frequencies. In addition, our data demonstrate that changes in distortion product otoacoustic emissions (DPOAEs) result from altered ME transmission in both the forward and reverse direction by a reduction of the effective stimulus levels and less efficient transfer of DPs from the ME into the ear canal. This confirms that DPOAEs can be used to assess both the health of the cochlea and the middle ear.
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Affiliation(s)
- Xiaohui Lin
- VA Loma Linda Healthcare System, Loma Linda, CA, 92374, USA
| | | | | | - Timothy T Jung
- VA Loma Linda Healthcare System, Loma Linda, CA, 92374, USA.,Department of Otolaryngology - Head and Neck Surgery, Loma Linda University Health, Loma Linda, CA, 92350, USA
| | - Glen K Martin
- VA Loma Linda Healthcare System, Loma Linda, CA, 92374, USA.,Department of Otolaryngology - Head and Neck Surgery, Loma Linda University Health, Loma Linda, CA, 92350, USA
| | - Wei Dong
- VA Loma Linda Healthcare System, Loma Linda, CA, 92374, USA. .,Department of Otolaryngology - Head and Neck Surgery, Loma Linda University Health, Loma Linda, CA, 92350, USA.
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8
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Rosowski JJ, Ramier A, Cheng JT, Yun SH. Optical coherence tomographic measurements of the sound-induced motion of the ossicular chain in chinchillas: Additional modes of ossicular motion enhance the mechanical response of the chinchilla middle ear at higher frequencies. Hear Res 2020; 396:108056. [PMID: 32836020 PMCID: PMC7572631 DOI: 10.1016/j.heares.2020.108056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/18/2020] [Accepted: 08/06/2020] [Indexed: 10/23/2022]
Abstract
Wavelength-swept optical coherence tomography (OCT) was used to scan the structure of cadaveric chinchilla ears in three dimensions with high spatial resolution and measure the sound-induced displacements of the entire OCT-visible lateral surfaces of the ossicles in the lateral-to-medial direction. The simultaneous measurement of structure and displacement allowed a precise match between the observed motion and its structural origin. The structure and measured displacements are consistent with previously published data. The coincident detailed structural and motion measurements demonstrate the presence of several frequency-dependent modes of ossicular motion, including: (i) rotation about an anteriorly-to-posteriorly directed axis positioned near the commonly defined anatomical axis of rotation that dominates at frequencies below 8 kHz, (ii) a lateral-to-medial translational component that is visible at frequencies from 2 to greater than 10 kHz, and (iii) a newly described rotational mode around an inferiorly-to-superiorly directed axis that parallels the manubrium of the malleus and dominates ossicular motion between 10 and 16 kHz. This new axis of rotation is located near the posterior edge of the manubrium. The onset of the second rotational mode leads to a boost in the magnitude of sound-induced stapes displacement near 14 kHz, and adds a half-cycle to the accumulating phase in middle-ear sound transmission. Similar measurements in one ear after interruption of the incudostapedial joint suggest the load of the cochlea and stapes annular ligament is important to the presence of the second rotational mode, and acts to limit simple ossicular translation.
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Affiliation(s)
- John J Rosowski
- Eaton-Peabody Laboratory of Auditory Physiology, Massachusetts Eye and Ear, 243 Charles Street, Boston 02114, MA, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, 243 Charles Street, Boston 02114, MA, USA.
| | - Antoine Ramier
- Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge 02139 MA, USA; Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Lansdowne St. UP-5, Cambridge 02139, MA, USA
| | - Jeffrey Tao Cheng
- Eaton-Peabody Laboratory of Auditory Physiology, Massachusetts Eye and Ear, 243 Charles Street, Boston 02114, MA, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, 243 Charles Street, Boston 02114, MA, USA
| | - Seok-Hyun Yun
- Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge 02139 MA, USA; Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Lansdowne St. UP-5, Cambridge 02139, MA, USA
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9
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Bernardi M, Couette S, Chateau Smith C, Montuire S. Middle ear pneumatization in nonhuman primates: A comparative analysis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 169:540-556. [DOI: 10.1002/ajpa.23848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 12/03/2018] [Accepted: 04/16/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Margot Bernardi
- EPHEPSL Research University Paris Paris France
- Biogéosciences, UMR 6282 CNRSUniversité Bourgogne Franche‐Comté Dijon France
| | - Sébastien Couette
- EPHEPSL Research University Paris Paris France
- Biogéosciences, UMR 6282 CNRSUniversité Bourgogne Franche‐Comté Dijon France
| | | | - Sophie Montuire
- EPHEPSL Research University Paris Paris France
- Biogéosciences, UMR 6282 CNRSUniversité Bourgogne Franche‐Comté Dijon France
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10
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Bowers P, Rosowski JJ. A lumped-element model of the chinchilla middle ear. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:1975. [PMID: 31046320 PMCID: PMC6464964 DOI: 10.1121/1.5094897] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 02/21/2019] [Accepted: 03/06/2019] [Indexed: 05/31/2023]
Abstract
An air-conduction circuit model was developed for the chinchilla middle ear and cochlea. The lumped-element model is based on the classic Zwislocki model of the same structures in human. Model parameters were fit to various measurements of chinchilla middle-ear transfer functions and impedances, using a combination of error-minimization-driven computer-automated and manual fitting methods. The measurements used to fit the model comprise a newer, more-extensive data set than previously used, and include measurements of stapes velocity and inner-ear sound pressure within the vestibule and the scala tympani near the round window. The model is in agreement with studies of the effects of middle-ear cavity holes in experiments that require access to the middle-ear air space. The structure of the model allows easy addition of other sources of auditory stimulation, e.g., the multiple sources of bone-conducted sound-the long-term goal for the model's development-and mechanical stimulation of the ossicles and round window.
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Affiliation(s)
- Peter Bowers
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, 243 Charles Street, Boston, Massachusetts 02114, USA
| | - John J Rosowski
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, 243 Charles Street, Boston, Massachusetts 02114, USA
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11
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Ramier A, Cheng JT, Ravicz ME, Rosowski JJ, Yun SH. Mapping the phase and amplitude of ossicular chain motion using sound-synchronous optical coherence vibrography. BIOMEDICAL OPTICS EXPRESS 2018; 9:5489-5502. [PMID: 30460142 PMCID: PMC6238908 DOI: 10.1364/boe.9.005489] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/10/2018] [Accepted: 09/12/2018] [Indexed: 05/21/2023]
Abstract
The sound-driven vibration of the tympanic membrane and ossicular chain of middle-ear bones is fundamental to hearing. Here we show that optical coherence tomography in phase synchrony with a sound stimulus is well suited for volumetric, vibrational imaging of the ossicles and tympanic membrane. This imaging tool - OCT vibrography - provides intuitive motion pictures of the ossicular chain and how they vary with frequency. Using the chinchilla ear as a model, we investigated the vibrational snapshots and phase delays of the manubrium, incus, and stapes over 100 Hz to 15 kHz. The vibrography images reveal a previously undescribed mode of motion of the chinchilla ossicles at high frequencies.
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Affiliation(s)
- Antoine Ramier
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
| | - Jeffrey Tao Cheng
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Michael E. Ravicz
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - John J. Rosowski
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Seok-Hyun Yun
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
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12
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Surface Motion of Tympanic Membrane in a Chinchilla Model of Acute Otitis Media. J Assoc Res Otolaryngol 2018; 19:619-635. [PMID: 30191424 DOI: 10.1007/s10162-018-00683-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/12/2018] [Indexed: 12/27/2022] Open
Abstract
The conductive hearing loss caused by acute otitis media (AOM) is commonly related to a reduction of the tympanic membrane (TM) mobility in response to sound stimuli. However, spatial alterations of the TM surface motion associated with AOM have rarely been addressed. In this study, the TM surface motion was determined using scanning laser Doppler vibrometry (SLDV) in a chinchilla model of AOM. The AOM was established by transbullar injection of nontypeable Haemophilus influenzae. The TM surface vibration was measured in control (uninfected) animals and two AOM groups of animals: 4 days (4D) and 8 days (8D) post inoculation. To quantify the effect of middle ear pressure in those infected ears, the SLDV measurement was first conducted in unopened AOM ears and then in middle ear pressure released ears. Results showed that middle ear infection generally reduced the TM displacement across the entire surface, but the reduction in the umbo displacement over the time course, from 4 to 8 days post inoculation, was less than the reduction in the displacement at the center of each quadrant. The presence of middle ear fluid shifted the occurrence of traveling-wave-like motion on the TM surface to lower frequencies. The observation of the spatial variations of TM surface motion from this study will help refine our understanding of the middle ear sound transmission characteristics in relation to AOM.
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13
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Ravicz ME, Rosowski JJ. Chinchilla middle ear transmission matrix model and middle-ear flexibility. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 141:3274. [PMID: 28599566 PMCID: PMC5435550 DOI: 10.1121/1.4982925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/12/2017] [Accepted: 04/20/2017] [Indexed: 06/07/2023]
Abstract
The function of the middle ear (ME) in transforming ME acoustic inputs and outputs (sound pressures and volume velocities) can be described with an acoustic two-port transmission matrix. This description is independent of the load on the ME (cochlea or ear canal) and holds in either direction: forward (from ear canal to cochlea) or reverse (from cochlea to ear canal). A transmission matrix describing ME function in chinchilla, an animal commonly used in auditory research, is presented, computed from measurements of forward ME function: input admittance YTM, ME pressure gain GMEP, ME velocity transfer function HV, and cochlear input admittance YC, in the same set of ears [Ravicz and Rosowski (2012b). J. Acoust. Soc. Am. 132, 2437-2454; (2013a). J. Acoust. Soc. Am. 133, 2208-2223; (2013b). J. Acoust. Soc. Am. 134, 2852-2865]. Unlike previous estimates, these computations require no assumptions about the state of the inner ear, effectiveness of ME manipulations, or measurements of sound transmission in the reverse direction. These element values are generally consistent with physical constraints and the anatomical ME "transformer ratio." Differences from a previous estimate in chinchilla [Songer and Rosowski (2007). J. Acoust. Soc. Am. 122, 932-942] may be due to a difference in ME flexibility between the two subject groups.
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Affiliation(s)
- Michael E Ravicz
- Eaton-Peabody Laboratory, Massachusetts Eye & Ear Infirmary, 243 Charles Street, Boston, Massachusetts 02114, USA
| | - John J Rosowski
- Eaton-Peabody Laboratory, Massachusetts Eye & Ear Infirmary, 243 Charles Street, Boston, Massachusetts 02114, USA
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14
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Milazzo M, Fallah E, Carapezza M, Kumar NS, Lei JH, Olson ES. The path of a click stimulus from ear canal to umbo. Hear Res 2017; 346:1-13. [PMID: 28087416 PMCID: PMC5348280 DOI: 10.1016/j.heares.2017.01.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/22/2016] [Accepted: 01/02/2017] [Indexed: 11/29/2022]
Abstract
The tympanic membrane (TM) has a key role in transmitting sounds to the inner ear, but a concise description of how the TM performs this function remains elusive. This paper probes TM operation by applying a free field click stimulus to the gerbil ear and exploring the consequent motions of the TM and umbo. Motions of the TM were measured both on radial tracks starting close to the umbo and on a grid distal and adjacent to the umbo. The experimental results confirmed the high fidelity of sound transmission from the ear canal to the umbo. A delay of 5-15 μs was seen in the onset of TM motion between points just adjacent to the umbo and mid-radial points. The TM responded with a ringing motion, with different locations possessing different primary ringing frequencies. A simple analytic model from the literature, treating the TM as a string, was used to explore the experimental results. The click-based experiments and analysis led to the following description of TM operation: A transient sound pressure on the TM causes a transient initial TM motion that is maximal ∼ at the TM's radial midpoints. Mechanical forces generated by this initial prominent TM distortion then pull the umbo inward, leading to a delayed umbo response. The initial TM deformation also gives rise to prolonged mechanical ringing on the TM that does not result in significant umbo motion, likely due to destructive interference from the range of ringing frequencies. Thus, the umbo's response is a high-fidelity representation of the transient stimulus. Because any sound can be considered as a consecutive series of clicks, this description is applicable to any sound stimulus.
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Affiliation(s)
- Mario Milazzo
- The BioRobotics Institute, Scuola Superiore Sant' Anna, Viale R. Piaggio 34, 56025 Pontedera, Italy
| | - Elika Fallah
- Department of Otolaryngology & Head and Neck Surgery, Department of Biomedical Engineering, Columbia University, 630 West 168th Street, P&S 11-452, New York, NY 10032, USA
| | - Michael Carapezza
- Department of Otolaryngology & Head and Neck Surgery, Department of Biomedical Engineering, Columbia University, 630 West 168th Street, P&S 11-452, New York, NY 10032, USA
| | - Nina S Kumar
- Department of Otolaryngology & Head and Neck Surgery, Department of Biomedical Engineering, Columbia University, 630 West 168th Street, P&S 11-452, New York, NY 10032, USA
| | - Jason H Lei
- Department of Otolaryngology & Head and Neck Surgery, Department of Biomedical Engineering, Columbia University, 630 West 168th Street, P&S 11-452, New York, NY 10032, USA
| | - Elizabeth S Olson
- Department of Otolaryngology & Head and Neck Surgery, Department of Biomedical Engineering, Columbia University, 630 West 168th Street, P&S 11-452, New York, NY 10032, USA.
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15
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Estimation of Round-Trip Outer-Middle Ear Gain Using DPOAEs. J Assoc Res Otolaryngol 2016; 18:121-138. [PMID: 27796594 DOI: 10.1007/s10162-016-0592-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 09/20/2016] [Indexed: 10/20/2022] Open
Abstract
The reported research introduces a noninvasive approach to estimate round-trip outer-middle ear pressure gain using distortion product otoacoustic emissions (DPOAEs). Our ability to hear depends primarily on sound waves traveling through the outer and middle ear toward the inner ear. The role of the outer and middle ear in sound transmission is particularly important for otoacoustic emissions (OAEs), which are sound signals generated in a healthy cochlea and recorded by a sensitive microphone placed in the ear canal. OAEs are used to evaluate the health and function of the cochlea; however, they are also affected by outer and middle ear characteristics. To better assess cochlear health using OAEs, it is critical to quantify the effect of the outer and middle ear on sound transmission. DPOAEs were obtained in two conditions: (i) two-tone and (ii) three-tone. In the two-tone condition, DPOAEs were generated by presenting two primary tones in the ear canal. In the three-tone condition, DPOAEs at the same frequencies (as in the two-tone condition) were generated by the interaction of the lower frequency primary tone in the two-tone condition with a distortion product generated by the interaction of two other external tones. Considering how the primary tones and DPOAEs of the aforementioned conditions were affected by the forward and reverse outer-middle ear transmission, an estimate of the round-trip outer-middle ear pressure gain was obtained. The round-trip outer-middle ear gain estimates ranged from -39 to -17 dB between 1 and 3.3 kHz.
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16
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Lemons C, Meaud J. Middle-ear function in the chinchilla: Circuit models and comparison with other mammalian species. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:2735. [PMID: 27794345 DOI: 10.1121/1.4964707] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The middle ear efficiently transmits sound from the ear canal into the inner ear through a broad range of frequencies. Thus, understanding middle-ear transmission characteristics is essential in the study of hearing mechanics. Two models of the chinchilla middle ear are presented. In the first model, the middle ear is modeled as a lumped parameter system with elements that represent the ossicular chain and the middle-ear cavity. Parameters of this model are fit using available experimental data of two-port transmission matrix parameters. In an effort to improve agreement between model simulations and the phase of published experimental measurements for the forward pressure transfer function at high frequencies, a second model in which a lossless transmission line model of the tympanic membrane is appended to the original model is proposed. Two-port transmission matrix parameter results from this second model were compared with results from previously developed models of the guinea pig, cat, and human middle ears. Model results and published experimental data for the two-port transmission matrix parameters are found to be qualitatively similar between species. Quantitative differences in the two-port transmission matrix parameters suggest that the ossicular chains of chinchillas, cats, and guinea pigs are less flexible than in humans.
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Affiliation(s)
- Charlsie Lemons
- G.W.W. School of Mechanical Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332, USA
| | - Julien Meaud
- G.W.W. School of Mechanical Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332, USA
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17
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3D finite element model of the chinchilla ear for characterizing middle ear functions. Biomech Model Mechanobiol 2016; 15:1263-77. [PMID: 26785845 DOI: 10.1007/s10237-016-0758-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 01/05/2016] [Indexed: 12/16/2022]
Abstract
Chinchilla is a commonly used animal model for research of sound transmission through the ear. Experimental measurements of the middle ear transfer function in chinchillas have shown that the middle ear cavity greatly affects the tympanic membrane (TM) and stapes footplate (FP) displacements. However, there is no finite element (FE) model of the chinchilla ear available in the literature to characterize the middle ear functions with the anatomical features of the chinchilla ear. This paper reports a recently completed 3D FE model of the chinchilla ear based on X-ray micro-computed tomography images of a chinchilla bulla. The model consisted of the ear canal, TM, middle ear ossicles and suspensory ligaments, and the middle ear cavity. Two boundary conditions of the middle ear cavity wall were simulated in the model as the rigid structure and the partially flexible surface, and the acoustic-mechanical coupled analysis was conducted with these two conditions to characterize the middle ear function. The model results were compared with experimental measurements reported in the literature including the TM and FP displacements and the middle ear input admittance in chinchilla ear. An application of this model was presented to identify the acoustic role of the middle ear septa-a unique feature of chinchilla middle ear cavity. This study provides the first 3D FE model of the chinchilla ear for characterizing the middle ear functions through the acoustic-mechanical coupled FE analysis.
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18
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Lewis JD, Neely ST. Non-invasive estimation of middle-ear input impedance and efficiency. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:977-93. [PMID: 26328714 PMCID: PMC4545079 DOI: 10.1121/1.4927408] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A method to transform the impedance measured in the ear canal, ZEC, to the plane of the eardrum, ZED, is described. The portion of the canal between the probe and eardrum was modeled as a concatenated series of conical segments, allowing for spatial variations in its cross-sectional area. A model of the middle ear (ME) and cochlea terminated the ear-canal model, which permitted estimation of ME efficiency. Acoustic measurements of ZEC were made at two probe locations in 15 normal-hearing subjects. ZEC was sensitive to measurement location, especially near frequencies of canal resonances and anti-resonances. Transforming ZEC to ZED reduced the influence of the canal, decreasing insertion-depth sensitivity of ZED between 1 and 12 kHz compared to ZEC. Absorbance, A, was less sensitive to probe placement than ZEC, but more sensitive than ZED above 5 kHz. ZED and A were similarly insensitive to probe placement between 1 and 5 kHz. The probe-placement sensitivity of ZED below 1 kHz was not reduced from that of either A or ZEC. ME efficiency had a bandpass shape with greatest efficiency between 1 and 4 kHz. Estimates of ZED and ME efficiency could extend the diagnostic capability of wideband-acoustic immittance measurements.
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Affiliation(s)
- James D Lewis
- Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA
| | - Stephen T Neely
- Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA
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19
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Robles L, Temchin AN, Fan YH, Ruggero MA. Stapes Vibration in the Chinchilla Middle Ear: Relation to Behavioral and Auditory-Nerve Thresholds. J Assoc Res Otolaryngol 2015; 16:447-57. [PMID: 26068200 DOI: 10.1007/s10162-015-0524-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 05/17/2015] [Indexed: 10/23/2022] Open
Abstract
The vibratory responses to tones of the stapes and incus were measured in the middle ears of deeply anesthetized chinchillas using a wide-band acoustic-stimulus system and a laser velocimeter coupled to a microscope. With the laser beam at an angle of about 40 ° relative to the axis of stapes piston-like motion, the sensitivity-vs.-frequency curves of vibrations at the head of the stapes and the incus lenticular process were very similar to each other but larger, in the range 15-30 kHz, than the vibrations of the incus just peripheral to the pedicle. With the laser beam aligned with the axis of piston-like stapes motion, vibrations of the incus just peripheral to its pedicle were very similar to the vibrations of the lenticular process or the stapes head measured at the 40 ° angle. Thus, the pedicle prevents transmission to the stapes of components of incus vibration not aligned with the axis of stapes piston-like motion. The mean magnitude curve of stapes velocities is fairly flat over a wide frequency range, with a mean value of about 0.19 mm(.)(s Pa(-1)), has a high-frequency cutoff of 25 kHz (measured at -3 dB re the mean value), and decreases with a slope of about -60 dB/octave at higher frequencies. According to our measurements, the chinchilla middle ear transmits acoustic signals into the cochlea at frequencies exceeding both the bandwidth of responses of auditory-nerve fibers and the upper cutoff of hearing. The phase lags of stapes velocity relative to ear-canal pressure increase approximately linearly, with slopes equivalent to pure delays of about 57-76 μs.
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Affiliation(s)
- Luis Robles
- Instituto de Ciencias Biomédicas (Facultad de Medicina), Universidad de Chile, Santiago, Chile
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