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Badlowski GA, Boyle KS. Repeated boat noise exposure damages inner ear sensory hair cells and decreases hearing sensitivity in Atlantic croaker (Micropogonias undulatus). J Exp Biol 2024; 227:jeb245093. [PMID: 38099450 DOI: 10.1242/jeb.245093] [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: 09/20/2022] [Accepted: 12/06/2023] [Indexed: 01/25/2024]
Abstract
Anthropogenic noise is becoming a major underwater pollutant because of rapidly increasing boat traffic worldwide. But its impact on aquatic organisms remains largely unknown. Previous studies have focused mainly on high-frequency and impulsive noises (i.e. sonar); however, boat noise is more pervasive, continuous, and its highest intensity and component frequencies overlap the auditory bandwidth of most fishes. We assessed the impacts of boat noise on saccular sensory hair cell density and hearing thresholds of a soniferous species, Atlantic croaker (Micropogonias undulatus). In two laboratory experiments, individuals were subjected to simulated boat noise: a single 15-min exposure and 3 days of intermittent noise (simulating passing vessels). Immediately after both experiments, fish were either (1) tested for hearing sensitivity with auditory evoked potential (AEP) tests or (2) euthanized for fluorescent phalloidin and TUNEL labeling for hair cell density counts. Relative to controls, no differences were observed in auditory thresholds nor hair cell density between individuals subjected to a single 15-min noise exposure. However, fish from the 3-day experiment showed decreased sensory hair cell density, increased apoptotic cells, and higher hearing thresholds than control fish at 300, 800 and 1000 Hz. Our results demonstrate that impacts from boat noise depend upon the duration and frequency of exposure. For a species reliant on vocalization for communication, these impacts may hinder spawning success, increase predation risks and significantly alter the ecosystem.
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Affiliation(s)
- Gina A Badlowski
- Department of Biological Sciences, University of New Orleans, New Orleans, LA 70148, USA
| | - Kelly S Boyle
- Department of Biological Sciences, University of New Orleans, New Orleans, LA 70148, USA
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Downregulation of GJB2 and SLC26A4 genes induced by noise exposure is associated with cochlear damage. Mol Biol Rep 2022; 49:7219-7229. [PMID: 35809183 DOI: 10.1007/s11033-022-07291-7] [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: 06/17/2021] [Revised: 01/08/2022] [Accepted: 02/22/2022] [Indexed: 10/17/2022]
Abstract
BACKGROUND Noise-induced hearing loss (NIHL) is one the major causes of acquired hearing loss in developed countries. Noise can change the pattern of gene expression, inducing sensorineural hearing impairment. There is no investigation on the effects of noise frequency on the expression of GJB2 and SLC26A4 genes involved in congenital hearing impairment in cochlear tissue. Here we investigated the impacts of white and purple noise on gene expression and pathologic changes of cochlear tissue. METHODS In this study, 32 adult male Westar rats were randomly divided into experimental groups: WN, animals exposed to white noise with a frequency range of 100-20000 Hz; PN, animals exposed to purple noise with a frequency range of 4-20 kHz, and control group, without noise. The experimental groups were exposed to a 118-120 dB sound pressure level for 8 h per 3 days and 6 days. 1 h and 1 week after termination of noise exposure, cochlear tissue was prepared for pathology and gene expression analysis. RESULTS Both white and purple noises caused permanent damage to the cortical, estrosilica systems of hair cells and ganglion of the hearing nerve. GJB2 and SLC26A4 were downregulated in both groups exposed with white and purple noise by increasing the time of noise exposure. However, differences are notably more significant in purple noise, which is more intensified. Also, 1 weak post noise exposure, the downregulation is remarkably higher than 1 h. CONCLUSIONS Our findings suggest that downregulation of GJB2 and SLC26A4 genes are associated with pathological injury in response to noise exposure in cochlear tissue. It would be suggested the demand for assessment of RNA and protein expression of genes involved in noise-induced hearing loss and subsequently the practice of hearing protection programs.
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Noise exposure levels predict blood levels of the inner ear protein prestin. Sci Rep 2022; 12:1154. [PMID: 35064195 PMCID: PMC8783004 DOI: 10.1038/s41598-022-05131-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 12/30/2021] [Indexed: 12/20/2022] Open
Abstract
Serological biomarkers of inner ear proteins are a promising new approach for studying human hearing. Here, we focus on the serological measurement of prestin, a protein integral to a human’s highly sensitive hearing, expressed in cochlear outer hair cells (OHCs). Building from recent nonhuman studies that associated noise-induced OHC trauma with reduced serum prestin levels, and studies suggesting subclinical hearing damage in humans regularly engaging in noisy activities, we investigated the relation between serum prestin levels and environmental noise levels in young adults with normal clinical audiograms. We measured prestin protein levels from circulating blood and collected noise level data multiple times over the course of the experiment using body-worn sound recorders. Results indicate that serum prestin levels have a negative relation with noise exposure: individuals with higher routine noise exposure levels tended to have lower prestin levels. Moreover, when grouping participants based on their risk for a clinically-significant noise-induced hearing loss, we found that prestin levels differed significantly between groups, even though behavioral hearing thresholds were similar. We discuss possible interpretations for our findings including whether lower serum levels may reflect subclinical levels of OHC damage, or possibly an adaptive, protective mechanism in which prestin expression is downregulated in response to loud environments.
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The integrity of cochlear hair cells is established and maintained through the localization of Dia1 at apical junctional complexes and stereocilia. Cell Death Dis 2020; 11:536. [PMID: 32678080 PMCID: PMC7366933 DOI: 10.1038/s41419-020-02743-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 02/07/2023]
Abstract
Dia1, which belongs to the diaphanous-related formin family, influences a variety of cellular processes through straight actin elongation activity. Recently, novel DIA1 mutants such as p.R1213X (p.R1204X) and p.A265S, have been reported to cause an autosomal dominant sensorineural hearing loss (DFNA1). Additionally, active DIA1 mutants induce progressive hearing loss in a gain-of-function manner. However, the subcellular localization and pathological function of DIA1(R1213X/R1204X) remains unknown. In the present study, we demonstrated the localization of endogenous Dia1 and the constitutively active DIA1 mutant in the cochlea, using transgenic mice expressing FLAG-tagged DIA1(R1204X) (DIA1-TG). Endogenous Dia1 and the DIA1 mutant were regionally expressed at the organ of Corti and the spiral ganglion from early life; alongside cochlear maturation, they became localized at the apical junctional complexes (AJCs) between hair cells (HCs) and supporting cells (SCs). To investigate HC vulnerability in the DIA1-TG mice, we exposed 4-week-old mice to moderate noise, which induced temporary threshold shifts with cochlear synaptopathy and ultrastructural changes in stereocilia 4 weeks post noise exposure. Furthermore, we established a knock-in (KI) mouse line expressing AcGFP-tagged DIA1(R1213X) (DIA1-KI) and confirmed mutant localization at AJCs and the tips of stereocilia in HCs. In MDCKAcGFP-DIA1(R1213X) cells with stable expression of AcGFP-DIA1(R1213X), AcGFP-DIA1(R1213X) revealed marked localization at microvilli on the apical surface of cells and decreased localization at cell-cell junctions. The DIA1-TG mice demonstrated hazy and ruffled circumferential actin belts at AJCs and abnormal stereocilia accompanied with HC loss at 5 months of age. In conclusion, Dia1 plays a pivotal role in the development and maintenance of AJCs and stereocilia, ensuring cochlear and HC integrity. Subclinical/latent vulnerability of HCs may be the cause of progressive hearing loss in DFNA1 patients, thus suggesting new therapeutic targets for preventing HC degeneration and progressive hearing loss associated with DFNA1.
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Fan L, Zhang Z, Wang H, Li C, Xing Y, Yin S, Chen Z, Wang J. Pre-exposure to Lower-Level Noise Mitigates Cochlear Synaptic Loss Induced by High-Level Noise. Front Syst Neurosci 2020; 14:25. [PMID: 32477075 PMCID: PMC7235317 DOI: 10.3389/fnsys.2020.00025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/16/2020] [Indexed: 12/20/2022] Open
Abstract
The auditory sensory organs appear to be less damaged by exposure to high-level noise that is presented after exposure to non-traumatizing low-level noise. This phenomenon is known as the toughening or conditioning effect. Functionally, it is manifested by a reduced threshold shift, and morphologically by a reduced hair cell loss. However, it remains unclear whether prior exposure to toughening noise can mitigate the synaptic loss induced by exposure to damaging noise. Since the cochlear afferent synapse between the inner hair cells and primary auditory neurons has been identified as a novel site involved in noise-induced cochlear damage, we were interested in assessing whether this synapse can be toughened. In the present study, the synaptic loss was induced by a damaging noise exposure (106 dB SPL) and compared across Guinea pigs who had and had not been previously exposed to a toughening noise (85 dB SPL). Results revealed that the toughening noise heavily reduced the synaptic loss observed 1 day after exposure to the damaging noise. Although it was significant, the protective effect of the toughening noise on permanent synaptic loss was much smaller. Compared with cases in the control group without noise exposure, coding deficits were seen in both toughened groups, as reflected in the compound action potential (CAP) by signals with amplitude modulation. In general, the pre-exposure to the toughening noise resulted in a significantly reduced synaptic loss by the high-level noise. However, this morphological protection was not accompanied by a robust functional benefit.
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Affiliation(s)
- Liqiang Fan
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Zhen Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Hui Wang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Chunyan Li
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Yazhi Xing
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Shankai Yin
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Zhengnong Chen
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Jian Wang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China.,School of Communication Sciences and Disorders, Faculty of Health, Dalhousie University, Halifax, NS, Canada
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Paired measurements of cochlear function and hair cell count in Dutch-belted rabbits with noise-induced hearing loss. Hear Res 2019; 385:107845. [PMID: 31760262 DOI: 10.1016/j.heares.2019.107845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/18/2019] [Accepted: 11/10/2019] [Indexed: 11/22/2022]
Abstract
The effects of noise-induced hearing loss have yet to be studied for the Dutch-belted strain of rabbits, which is the only strain that has been used in studies of the central auditory system. We measured auditory brainstem responses (ABRs), 2f1-f2 distortion product otoacoustic emissions (DPOAEs), and counts of cochlear inner and outer hair cells (IHCs and OHCs, respectively) from confocal images of Myo7a-stained cochlear whole-mounts in unexposed and noise-overexposed, Dutch-belted, male and female rabbits in order to characterize cochlear function and structure under normal-hearing and hearing-loss conditions. Using an octave-band noise exposure centered at 750 Hz presented under isoflurane anesthesia, we found that a sound level of 133 dB SPL for 60 min was minimally sufficient to produce permanent ABR threshold shifts. Overexposure durations of 60 and 90 min caused median click-evoked ABR threshold shifts of 10 and 50 dB, respectively. Susceptibility to overexposure was highly variable across ears, but less variable across test frequencies within the same ear. ABR and DPOAE threshold shifts were smaller, on average, and more variable in male than female ears. Similarly, post-exposure survival of OHCs was higher, on average, and more variable in male than female ears. We paired post-exposure ABR and DPOAE threshold shift data with hair cell count data measured in the same ear at the same frequency and cochlear frequency location. ABR and DPOAE threshold shifts exhibited critical values of 46 and 18 dB, respectively, below which the majority of OHCs and IHCs survived and above which OHCs were wiped out while IHC survival was variable. Our data may be of use to researchers who wish to use Dutch-belted rabbits as a model for the effects of noise-induced hearing loss on the central auditory system.
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Trevino M, Lobarinas E, Maulden AC, Heinz MG. The chinchilla animal model for hearing science and noise-induced hearing loss. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3710. [PMID: 31795699 PMCID: PMC6881193 DOI: 10.1121/1.5132950] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 05/07/2023]
Abstract
The chinchilla animal model for noise-induced hearing loss has an extensive history spanning more than 50 years. Many behavioral, anatomical, and physiological characteristics of the chinchilla make it a valuable animal model for hearing science. These include similarities with human hearing frequency and intensity sensitivity, the ability to be trained behaviorally with acoustic stimuli relevant to human hearing, a docile nature that allows many physiological measures to be made in an awake state, physiological robustness that allows for data to be collected from all levels of the auditory system, and the ability to model various types of conductive and sensorineural hearing losses that mimic pathologies observed in humans. Given these attributes, chinchillas have been used repeatedly to study anatomical, physiological, and behavioral effects of continuous and impulse noise exposures that produce either temporary or permanent threshold shifts. Based on the mechanistic insights from noise-exposure studies, chinchillas have also been used in pre-clinical drug studies for the prevention and rescue of noise-induced hearing loss. This review paper highlights the role of the chinchilla model in hearing science, its important contributions, and its advantages and limitations.
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Affiliation(s)
- Monica Trevino
- School of Behavioral and Brain Sciences, Callier Center, The University of Texas at Dallas, 1966 Inwood Road, Dallas, Texas 75235, USA
| | - Edward Lobarinas
- School of Behavioral and Brain Sciences, Callier Center, The University of Texas at Dallas, 1966 Inwood Road, Dallas, Texas 75235, USA
| | - Amanda C Maulden
- Department of Speech, Language, and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, Indiana 47907, USA
| | - Michael G Heinz
- Weldon School of Biomedical Engineering, Purdue University, 715 Clinic Drive, West Lafayette, Indiana 47907, USA
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Le TN, Straatman LV, Lea J, Westerberg B. Current insights in noise-induced hearing loss: a literature review of the underlying mechanism, pathophysiology, asymmetry, and management options. J Otolaryngol Head Neck Surg 2017; 46:41. [PMID: 28535812 PMCID: PMC5442866 DOI: 10.1186/s40463-017-0219-x] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/15/2017] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Noise-induced hearing loss is one of the most common forms of sensorineural hearing loss, is a major health problem, is largely preventable and is probably more widespread than revealed by conventional pure tone threshold testing. Noise-induced damage to the cochlea is traditionally considered to be associated with symmetrical mild to moderate hearing loss with associated tinnitus; however, there is a significant number of patients with asymmetrical thresholds and, depending on the exposure, severe to profound hearing loss as well. MAIN BODY Recent epidemiology and animal studies have provided further insight into the pathophysiology, clinical findings, social and economic impacts of noise-induced hearing loss. Furthermore, it is recently shown that acoustic trauma is associated with vestibular dysfunction, with associated dizziness that is not always measurable with current techniques. Deliberation of the prevalence, treatment and prevention of noise-induced hearing loss is important and timely. Currently, prevention and protection are the first lines of defence, although promising protective effects are emerging from multiple different pharmaceutical agents, such as steroids, antioxidants and neurotrophins. CONCLUSION This review provides a comprehensive update on the pathophysiology, investigations, prevalence of asymmetry, associated symptoms, and current strategies on the prevention and treatment of noise-induced hearing loss.
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Affiliation(s)
- Trung N. Le
- Division of Otolaryngology - Head & Neck Surgery, Department of Surgery, University of British Columbia, Vancouver, BC Canada
| | - Louise V. Straatman
- Division of Otolaryngology - Head & Neck Surgery, Department of Surgery, University of British Columbia, Vancouver, BC Canada
| | - Jane Lea
- Division of Otolaryngology - Head & Neck Surgery, Department of Surgery, University of British Columbia, Vancouver, BC Canada
| | - Brian Westerberg
- Division of Otolaryngology - Head & Neck Surgery, Department of Surgery, University of British Columbia, Vancouver, BC Canada
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Smith ME. Relationship Between Hair Cell Loss and Hearing Loss in Fishes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 875:1067-74. [PMID: 26611069 DOI: 10.1007/978-1-4939-2981-8_132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Exposure to intense sound or ototoxic chemicals can damage the auditory hair cells of vertebrates, resulting in hearing loss. Although the relationship between such hair cell damage and auditory function is fairly established for terrestrial vertebrates, there are limited data available to understand this relationship in fishes. Although investigators have measured either the morphological damage of the inner ear or the functional deficits in the hearing of fishes, very few have directly measured both in an attempt to find a relationship between the two. Those studies that have examined both auditory hair cell damage in the inner ear and the resulting hearing loss in fishes are reviewed here. In general, there is a significant linear relationship between the number of hair cells lost and the severity of hearing threshold shifts, although this varies between species and different hair cell-damaging stimuli. After trauma to the fish ear, auditory hair cells are able to regenerate to control level densities. With this regeneration also comes a restoration of hearing. Thus there is also a significant relationship between hair cell recovery and hearing recovery in fishes.
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Affiliation(s)
- Michael E Smith
- Department of Biology, Western Kentucky University, Bowling Green, KY, 42101, USA.
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Sanz L, Murillo-Cuesta S, Cobo P, Cediel-Algovia R, Contreras J, Rivera T, Varela-Nieto I, Avendaño C. Swept-sine noise-induced damage as a hearing loss model for preclinical assays. Front Aging Neurosci 2015; 7:7. [PMID: 25762930 PMCID: PMC4329813 DOI: 10.3389/fnagi.2015.00007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 01/19/2015] [Indexed: 11/27/2022] Open
Abstract
Mouse models are key tools for studying cochlear alterations in noise-induced hearing loss (NIHL) and for evaluating new therapies. Stimuli used to induce deafness in mice are usually white and octave band noises that include very low frequencies, considering the large mouse auditory range. We designed different sound stimuli, enriched in frequencies up to 20 kHz (“violet” noises) to examine their impact on hearing thresholds and cochlear cytoarchitecture after short exposure. In addition, we developed a cytocochleogram to quantitatively assess the ensuing structural degeneration and its functional correlation. Finally, we used this mouse model and cochleogram procedure to evaluate the potential therapeutic effect of transforming growth factor β1 (TGF-β1) inhibitors P17 and P144 on NIHL. CBA mice were exposed to violet swept-sine noise (VS) with different frequency ranges (2–20 or 9–13 kHz) and levels (105 or 120 dB SPL) for 30 min. Mice were evaluated by auditory brainstem response (ABR) and otoacoustic emission tests prior to and 2, 14 and 28 days after noise exposure. Cochlear pathology was assessed with gross histology; hair cell number was estimated by a stereological counting method. Our results indicate that functional and morphological changes induced by VS depend on the sound level and frequency composition. Partial hearing recovery followed the exposure to 105 dB SPL, whereas permanent cochlear damage resulted from the exposure to 120 dB SPL. Exposure to 9–13 kHz noise caused an auditory threshold shift (TS) in those frequencies that correlated with hair cell loss in the corresponding areas of the cochlea that were spotted on the cytocochleogram. In summary, we present mouse models of NIHL, which depending on the sound properties of the noise, cause different degrees of cochlear damage, and could therefore be used to study molecules which are potential players in hearing loss protection and repair.
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Affiliation(s)
- Lorena Sanz
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Príncipe de Asturias University Hospital, University of Alcalá, Alcalá de Henares Madrid, Spain
| | - Silvia Murillo-Cuesta
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
| | - Pedro Cobo
- Institute for Physical and Information Technologies (ITEFI), Spanish National Research Council (CSIC) Madrid, Spain
| | - Rafael Cediel-Algovia
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Veterinary Faculty, Complutense University of Madrid Madrid, Spain
| | - Julio Contreras
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Veterinary Faculty, Complutense University of Madrid Madrid, Spain
| | - Teresa Rivera
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Príncipe de Asturias University Hospital, University of Alcalá, Alcalá de Henares Madrid, Spain
| | - Isabel Varela-Nieto
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
| | - Carlos Avendaño
- Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain ; Department of Anatomy, Histology and Neuroscience, Medical School, Autónoma University of Madrid Madrid, Spain
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Chertoff ME, Earl BR, Diaz FJ, Sorensen JL, Thomas MLA, Kamerer AM, Peppi M. Predicting the location of missing outer hair cells using the electrical signal recorded at the round window. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2014; 136:1212. [PMID: 25190395 PMCID: PMC4165229 DOI: 10.1121/1.4890641] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 06/27/2014] [Accepted: 07/07/2014] [Indexed: 06/01/2023]
Abstract
The electrical signal recorded at the round window was used to estimate the location of missing outer hair cells. The cochlear response was recorded to a low frequency tone embedded in high-pass filtered noise conditions. Cochlear damage was created by either overexposure to frequency-specific tones or laser light. In animals with continuous damage along the partition, the amplitude of the cochlear response increased as the high-pass cutoff frequency increased, eventually reaching a plateau. The cochlear distance at the onset of the plateau correlated with the anatomical onset of outer hair cell loss. A mathematical model replicated the physiologic data but was limited to cases with continuous hair cell loss in the middle and basal turns. The neural contribution to the cochlear response was determined by recording the response before and after application of Ouabain. Application of Ouabain eliminated or reduced auditory neural activity from approximately two turns of the cochlea. The amplitude of the cochlear response was reduced for moderate signal levels with a limited effect at higher levels, indicating that the cochlear response was dominated by outer hair cell currents at high signal levels and neural potentials at low to moderate signal levels.
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MESH Headings
- Animals
- Audiometry, Pure-Tone
- Auditory Threshold
- Cochlear Microphonic Potentials/drug effects
- Disease Models, Animal
- Female
- Gerbillinae
- Hair Cells, Auditory, Outer/drug effects
- Hair Cells, Auditory, Outer/pathology
- Hearing Loss, Noise-Induced/etiology
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Lasers
- Models, Biological
- Ouabain/pharmacology
- Round Window, Ear/injuries
- Round Window, Ear/innervation
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Affiliation(s)
- Mark E Chertoff
- Department of Hearing and Speech, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Brian R Earl
- Department of Communication Sciences and Disorders, University of Cincinnati, Cincinnati, Ohio 45267
| | - Francisco J Diaz
- Department of Biostatistics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Janna L Sorensen
- Department of Hearing and Speech, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Megan L A Thomas
- Hearing and Balance Center, Boys Town National Research Hospital, Omaha, Nebraska 68131
| | - Aryn M Kamerer
- Department of Hearing and Speech, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Marcello Peppi
- Department of Hearing and Speech, University of Kansas Medical Center, Kansas City, Kansas 66160
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Moshammer H, Kundi M, Wallner P, Herbst A, Feuerstein A, Hutter HP. Early prognosis of noise-induced hearing loss. Occup Environ Med 2014; 72:85-9. [DOI: 10.1136/oemed-2014-102200] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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13
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Alvarado JC, Fuentes-Santamaría V, Jareño-Flores T, Blanco JL, Juiz JM. Normal variations in the morphology of auditory brainstem response (ABR) waveforms: a study in Wistar rats. Neurosci Res 2012; 73:302-11. [PMID: 22595234 DOI: 10.1016/j.neures.2012.05.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 05/01/2012] [Accepted: 05/02/2012] [Indexed: 10/28/2022]
Abstract
Auditory brainstem evoked responses (ABR) have been used for decades to assess auditory function. Surprisingly, despite the fact that rats are one of the most widely used experimental models in hearing, there have been no studies that have characterized in detail the normal morphological variations that occur in ABR waves. Therefore, the goal of this study was to characterize the patterns of ABR waves in rats to establish baseline criteria that could be used to identify abnormalities. Rats were stimulated with pure tone sounds at different frequencies and ABR waves were classified based on morphology. The most definitive finding was that, unlike what is observed in human ABRs, wave II of the rat ABR was the most prominent. Additionally, wave III was the smallest and, in many cases, was not apparent at low frequencies. Wave III was frequently involved in the formation of complexes, often appearing as a small wave or adjoining primarily wave IV. Complexes were common at low and medium frequencies and rare at high frequencies. These results indicate that knowledge of the different wave patterns in normal rats is fundamental to understanding how the wave morphology changes in pathological conditions that could lead to hearing impairment.
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Affiliation(s)
- Juan Carlos Alvarado
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), 02006 Albacete, Spain.
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14
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Le Prell CG, Dolan DF, Bennett DC, Boxer PA. Nutrient plasma levels achieved during treatment that reduces noise-induced hearing loss. Transl Res 2011; 158:54-70. [PMID: 21708356 PMCID: PMC3125531 DOI: 10.1016/j.trsl.2011.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 02/04/2011] [Accepted: 02/07/2011] [Indexed: 10/18/2022]
Abstract
Hearing loss encompasses both temporary and permanent deficits. If temporary threshold shift (TTS) and permanent threshold shift (PTS) share common pathological mechanisms, then agents that reduce PTS also should reduce TTS. Several antioxidant agents have reduced PTS in rodent models; however, reductions in TTS have been inconsistent. This study first determined whether dietary antioxidants (beta-carotene and vitamins C and E) delivered in combination with magnesium (Mg) reliably increase plasma concentrations of the active agents. Then, additional manipulations tested the hypothesis that these nutrients reduce acute TTS insult in the first 24 h after loud sound as well as longer lasting changes in hearing measured up to 7 days postnoise. Saline or nutrients were administered to guinea pigs prior to and after noise exposure. Sound-evoked electrophysiological responses were measured before noise, with tests repeated 1-h postnoise, as well as 1-day, 3-days, 5-days, and 7-days postnoise. All subjects showed significant functional recovery; subjects treated with nutrients recovered more rapidly and had better hearing outcomes at early postnoise times as well as the final test time. Thus, this combination of nutrients, which produced significant increases in plasma concentrations of vitamins C and E and Mg, effectively reduced hearing loss at multiple postnoise times. These data suggest that free radical formation contributes to TTS as well as PTS insults and suggest a potential opportunity to prevent TTS in human populations.
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Affiliation(s)
- Colleen G Le Prell
- Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, FL 32610, USA.
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15
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Wang H, Brozoski TJ, Ling L, Hughes LF, Caspary DM. Impact of sound exposure and aging on brain-derived neurotrophic factor and tyrosine kinase B receptors levels in dorsal cochlear nucleus 80 days following sound exposure. Neuroscience 2011; 172:453-9. [PMID: 21034795 PMCID: PMC3057525 DOI: 10.1016/j.neuroscience.2010.10.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 10/18/2010] [Accepted: 10/19/2010] [Indexed: 11/22/2022]
Abstract
Recent studies suggested that acute sound exposure resulting in a temporary threshold shift in young adult animals within a series of maladaptive plasticity changes in central auditory structures. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, is involved in post-trauma peripheral hair cell and spiral ganglion cell survival and has been shown to modulate synaptic strength in cochlear nucleus following sound exposure. The present study evaluated levels of BDNF and its receptor (tyrosine kinase B, [TrkB]) in the dorsal cochlear nucleus (DCN) following a unilateral moderate sound exposure in young (7-8 months) and aged (28-29 months) Fischer Brown Norway (FBN) rats. Eighty days post-exposure, auditory brainstem response (ABR) thresholds for young exposed rats approached control values while aged exposed rats showed residual permanent threshold shifts (PTS) relative to aged controls. BDNF protein levels were significantly up-regulated by 9% in young exposed fusiform cells ipsilateral to the exposure. BDNF levels in aged sound-exposed fusiform cells increased 31% ipsilateral to the exposure. Protein levels of the BDNF receptor, TrkB, were also significantly increased in aged but not in young sound-exposed DCN fusiform cells. The present findings suggest a relationship between the up-regulation of BDNF/TrkB and the increase in spontaneous and driven activity previously observed for aged and sound-exposed fusiform cells. This might be due to a selective maladaptive compensatory down-regulation of glycinergic inhibition in DCN fusiform cells.
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MESH Headings
- Acoustic Stimulation/adverse effects
- Acoustic Stimulation/methods
- Aging/metabolism
- Animals
- Brain-Derived Neurotrophic Factor/biosynthesis
- Brain-Derived Neurotrophic Factor/metabolism
- Cell Survival/physiology
- Cochlear Nucleus/metabolism
- Cochlear Nucleus/pathology
- Cochlear Nucleus/physiopathology
- Disease Models, Animal
- Hearing Loss, Central/metabolism
- Hearing Loss, Central/pathology
- Hearing Loss, Central/physiopathology
- Hearing Loss, Noise-Induced/metabolism
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Male
- Noise/adverse effects
- Rats
- Rats, Inbred F344
- Receptor, trkB/biosynthesis
- Receptor, trkB/metabolism
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Affiliation(s)
- Hongning Wang
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, IL 62794-9629, USA
| | - Thomas J. Brozoski
- Department of Surgery, Southern Illinois University School of Medicine, Springfield, IL 62794-9629, USA
| | - Lynne Ling
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, IL 62794-9629, USA
| | - Larry F. Hughes
- Department of Surgery, Southern Illinois University School of Medicine, Springfield, IL 62794-9629, USA
| | - Donald M. Caspary
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, IL 62794-9629, USA
- Department of Surgery, Southern Illinois University School of Medicine, Springfield, IL 62794-9629, USA
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Adelman C, Weinberger JM, Sohmer H. Reduced salicylic acid binding following noise: possible evidence for prestin disruption. J Basic Clin Physiol Pharmacol 2010; 21:211-9. [PMID: 21166269 DOI: 10.1515/jbcpp.2010.21.3.211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To gain insight into the mechanism of noise induced permanent threshold shift (PTS), the magnitude of the auditory threshold elevation induced by injection of salicylic acid (which competitively binds with the motor protein prestin) to animals with a pre-existing PTS was compared to that in control animals (not exposed to noise). Normal mice were exposed to a noise intensity and duration which causes a small PTS. After determining the degree of the resulting PTS two weeks following the noise, salicylic acid was injected. The salicylic acid induced an additional threshold elevation and its magnitude was compared to that in control mice which had not been noise exposed. The mean noise induced PTS in the experimental (noise exposed) group was 25.5 dB. Following the administration of salicylic acid to these animals, there was an additional (salicylic acid induced) mean threshold elevation of 17.5 dB, and this was significantly smaller than that in control (not noise exposed) mice (36.8 dB). This may be evidence for a reduced number of salicylic acid binding sites on prestin and therefore the PTS may be due to disruption of prestin by the free radicals produced during the noise exposure.
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Affiliation(s)
- Cahtia Adelman
- Speech & Hearing Center, Hadassah University Hospital, Jerusalem, Israel
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17
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Zhu X, Kim JH, Song WJ, Murphy WJ, Song S. Development of a noise metric for assessment of exposure risk to complex noises. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2009; 126:703-12. [PMID: 19640036 DOI: 10.1121/1.3159587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Many noise guidelines currently use A-weighted equivalent sound pressure level L(Aeq) as the noise metric and the equal energy hypothesis to assess the risk of occupational noises. Because of the time-averaging effect involved with the procedure, the current guidelines may significantly underestimate the risk associated with complex noises. This study develops and evaluates several new noise metrics for more accurate assessment of exposure risks to complex and impulsive noises. The analytic wavelet transform was used to obtain time-frequency characteristics of the noise. 6 basic, unique metric forms that reflect the time-frequency characteristics were developed, from which 14 noise metrics were derived. The noise metrics were evaluated utilizing existing animal test data that were obtained by exposing 23 groups of chinchillas to, respectively, different types of noise. Correlations of the metrics with the hearing losses observed in chinchillas were compared and the most promising noise metric was identified.
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Affiliation(s)
- Xiangdong Zhu
- Department of Mechanical Engineering, University of Cincinnati, Cincinnati, OH 45221-0072, USA
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18
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Marshall L, Lapsley Miller JA, Heller LM, Wolgemuth KS, Hughes LM, Smith SD, Kopke RD. Detecting incipient inner-ear damage from impulse noise with otoacoustic emissions. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2009; 125:995-1013. [PMID: 19206875 DOI: 10.1121/1.3050304] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Audiometric thresholds and otoacoustic emissions (OAEs) were measured in 285 U.S. Marine Corps recruits before and three weeks after exposure to impulse-noise sources from weapons' fire and simulated artillery, and in 32 non-noise-exposed controls. At pre-test, audiometric thresholds for all ears were <or=25 dB HL from 0.5 to 3 kHz and <or=30 dB HL at 4 kHz. Ears with low-level or absent OAEs at pre-test were more likely to be classified with significant threshold shifts (STSs) at post-test. A subgroup of 60 noise-exposed volunteers with complete data sets for both ears showed significant decreases in OAE amplitude but no change in audiometric thresholds. STSs and significant emission shifts (SESs) between 2 and 4 kHz in individual ears were identified using criteria based on the standard error of measurement from the control group. There was essentially no association between the occurrence of STS and SES. There were more SESs than STSs, and the group of SES ears had more STS ears than the group of no-SES ears. The increased sensitivity of OAEs in comparison to audiometric thresholds was shown in all analyses, and low-level OAEs indicate an increased risk of future hearing loss by as much as ninefold.
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Affiliation(s)
- Lynne Marshall
- Naval Submarine Medical Research Laboratory, Groton, Connecticut 06349-5900, USA.
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19
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The Effects of Aging on Distortion-Product Otoacoustic Emissions in Adults with Normal Hearing. Ear Hear 2008; 29:176-84. [DOI: 10.1097/aud.0b013e3181634eb8] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Hamernik RP, Qiu W, Davis B. Hearing loss from interrupted, intermittent, and time varying non-Gaussian noise exposure: The applicability of the equal energy hypothesis. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2007; 122:2245-54. [PMID: 17902860 DOI: 10.1121/1.2775160] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Sixteen groups of chinchillas (N=140) were exposed to various equivalent energy noise paradigms at 100 dB(A) or 103 dB(A) SPL. Eleven groups received an interrupted, intermittent, and time varying (IITV) non-Gaussian exposure quantified by the kurtosis statistic. The IITV exposures, which lasted for 8 hday, 5 daysweek for 3 weeks, were designed to model some of the essential features of an industrial workweek. Five equivalent energy reference groups were exposed to either a Gaussian or non-Gaussian 5 days, 24 hday continuous noise. Evoked potentials were used to estimate hearing thresholds and surface preparations of the organ of Corti quantified the sensory cell population. For IITV exposures at an equivalent energy and kurtosis, the temporal variations in level did not alter trauma and in some cases the IITV exposures produced results similar to those found for the 5 day continuous exposures. Any increase in kurtosis at a fixed energy was accompanied by an increase in noise-induced trauma. These results suggest that the equal energy hypothesis is an acceptable approach to evaluating noise exposures for hearing conservation purposes provided that the kurtosis of the amplitude distribution is taken into consideration. Temporal variations in noise levels seem to have little effect on trauma.
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Affiliation(s)
- Roger P Hamernik
- Auditory Research Laboratory, State University of New York at Plattsburgh, 107 Beaumont Hall, Plattsburgh, New York 12901, USA.
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21
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Shupak A, Tal D, Sharoni Z, Oren M, Ravid A, Pratt H. Otoacoustic Emissions in Early Noise-Induced Hearing Loss. Otol Neurotol 2007; 28:745-52. [PMID: 17721363 DOI: 10.1097/mao.0b013e3180a726c9] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To follow changes in transient evoked and distortion product otoacoustic emissions (TEOAEs, DPOAEs) as they relate to pure-tone audiometry (PTaud) thresholds during the first 2 years of occupational noise exposure. DESIGN Prospective controlled. METHODS Pure-tone audiometry thresholds, TEOAE and DPOAE amplitudes, and contralateral medial olivocochlear reflex strength were repeatedly evaluated during 2 years and compared between and within a cohort of 135 ship engine room recruits and a control group of 100 subjects with no noise exposure. RESULTS Pure-tone audiometry thresholds for 2,000, 3,000 and 4,000 Hz in both ears were significantly elevated in the study group after 2 years of noise exposure. Significantly lower TEOAE amplitudes were found at 2,000 Hz in the right ear and 2,000 and 4,000 Hz in the left ear. Longitudinal intrasubject analysis of the study group revealed significant reductions of TEOAE amplitudes at 2,000 to 4,000 Hz in both ears and reduced DPOAE amplitudes for 5,957 Hz in the right ear and 3,809, 4,736, and 5,957 Hz in the left ear in the second follow-up evaluation. Baseline medial olivocochlear reflex strength showed no correlation to PTaud thresholds after 2 years of noise exposure. Poor to moderate negative linear correlations (r = -0.07 to -0.37) were found between the DPOAE-averaged amplitudes at 2,979 to 5,957 Hz and PTaud threshold means at 3,000 to 6,000 Hz. Abnormal TEOAE parameters after the first year of noise exposure had high sensitivity (86-88%) and low specificity (33-35%) for the prediction of noise-induced hearing loss (NIHL) after 2 years. CONCLUSION The DP-gram is not significantly correlated with PTaud and cannot be used as an objective measure of pure-tone thresholds in early NIHL. Medial olivocochlear reflex strength before the beginning of chronic exposure to occupational noise has no relation to individual vulnerability to NIHL. Although TEOAEs changes after 1 year showed high sensitivity in predicting NIHL after 2 years of exposure, they cannot be recommended as an efficient screening tool due to high false-positive rates.
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Affiliation(s)
- Avi Shupak
- Unit of Otoneurology, Carmel and Lin Medical Centre, Haifa, Israel.
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22
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Qiu W, Davis B, Hamernik RP. Hearing loss from interrupted, intermittent, and time varying Gaussian noise exposures: the applicability of the equal energy hypothesis. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2007; 121:1613-20. [PMID: 17407898 DOI: 10.1121/1.2434692] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Eight groups of chinchillas (N=74) were exposed to various equivalent energy [100 or 106 dB(A) sound pressure level (SPL)] noise exposure paradigms. Six groups received an interrupted, intermittent, time varying (IITV) Gaussian noise exposure that lasted 8 h/d, 5 d/week for 3 weeks. The exposures modeled an idealized workweek. At each level, three different temporal patterns of Gaussian IITV noise were used. The 100 dB(A) IITV exposure had a dB range of 90-108 dB SPL while the range of the 106 dB(A) IITV exposure was 80-115 dB SPL. Two reference groups were exposed to a uniform 100 or 106 dB(A) SPL noise, 24 h/d for 5 days. Each reference group and the three corresponding IITV groups comprised a set of equivalent energy exposures. Evoked potentials were used to estimate hearing thresholds and surface preparation histology quantified sensory cell populations. All six groups exposed to the IITV noise showed threshold toughening effects of up to 40 dB. All IITV exposures produced hearing and sensory cell loss that was similar to their respective equivalent energy reference group. These results indicate that for Gaussian noise the equal energy hypothesis for noise-induced hearing loss is an acceptable unifying principle.
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Affiliation(s)
- Wei Qiu
- Auditory Research Laboratory, State University of New York, 107 Beaumont Hall, Plattsburgh, New York 12901, USA.
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23
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Porter CA, Martin GK, Stagner BB, Lonsbury-Martin BL. Distortion-product otoacoustic emission suppression growth in normal and noise-exposed rabbits. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2006; 120:884-900. [PMID: 16938977 DOI: 10.1121/1.2211407] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This study investigated noise-induced changes in suppression growth (SG) of distortion product otoacoustic emissions (DPOAEs). Detailed measurements of SG were obtained in rabbits as a function of f2 frequencies at four primary-tone levels. SG measures were produced by using suppressor tones (STs) presented at two fixed distances from f2. The magnitude of suppression was calculated for each ST level and depicted as contour plots showing the amount of suppression as a function of the f2 frequency. At each f2, SG indices included slope, suppression threshold, and an estimate of the tip-to-tail value. All suppression measures were obtained before and after producing a cochlear dysfunction using a monaural exposure to a 2-h, 110-dB SPL octave-band noise centered at 2 kHz. The noise exposure produced varying amounts of cochlear damage as revealed by changes in DP-grams and auditory brainstem responses. However, average measures of SG slopes, suppression thresholds, and tip-to-tail values failed to mirror the mean DP-gram loss patterns. When suppression-based parameters were correlated with the amount of DPOAE loss, small but significant correlations were observed for some measures. Overall, the findings suggest that measures derived from DPOAE SG are limited in their ability to detect noise-induced cochlear damage.
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Affiliation(s)
- Christopher A Porter
- School of Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80203, USA
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24
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Emmerich E, Richter F, Linss V, Linss W. Frequency-specific cochlear damage in guinea pig after exposure to different types of realistic industrial noise. Hear Res 2005; 201:90-8. [PMID: 15721564 DOI: 10.1016/j.heares.2004.09.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Accepted: 09/14/2004] [Indexed: 11/16/2022]
Abstract
For the causal evaluation of occupational hearing damage it is important to identify definitely the noise source. Here we tested, whether recordings of distortion product otoacoustic emissions (DPOAEs) in awake guinea pigs can distinguish the effects of different industrial noises. Six groups of 12 animals each were investigated before and over four months after a single 2 h exposure to specific, played-back industrial noise as well as before and for 2 months after impulse noise exposure. We compared broadband noise (buzz saw, bottle washing machine), low frequency noise (drawing press), and mid-frequency noise (bottle filling machine). All animals had stable DPOAE levels before noise exposure. Frequency specific decreases in DPOAEs were found after exposure to the different noises. Broadband noise diminished mostly all frequencies tested, whereas low- or mid-frequency noise had a greater effect on DPOAE evoked by middle and higher frequencies, respectively. DPOAE evoked by middle and higher frequencies were obliterated after impulse noise. Morphological analysis of the cochleae confirmed these alterations. OHC loss was found in the middle turns of the cochleae corresponding to the diminution of DPOAE. We conclude that different kinds of industrial noise tend to produce typical changes in DPOAE levels.
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Affiliation(s)
- Edeltraut Emmerich
- Institute of Physiology-Neurophysiology, Friedrich Schiller University Jena, Teichgraben 8, D-07740 Jena, Germany.
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Pouyatos B, Campo P, Lataye R. Influence of age on noise- and styrene-induced hearing loss in the Long-Evans rat. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2005; 19:561-570. [PMID: 21783527 DOI: 10.1016/j.etap.2004.12.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This paper reviews different investigations carried out with Long-Evans rats on the influence of age on the ototoxicity induced by styrene and on the vulnerability to noise. The first part of this article is focused on the differences in auditory susceptibility to noise (92 or 97dB octave band noise centered at 8kHz, 6 h/day, 5 days/week, 4 weeks) and styrene (700ppm, 6h/d, 5 d/w, 4 w) between young (three and half months) and old (24 months) Long-Evans rats. Auditory evoked potential measures revealed that the old rats tend to be more sensitive than young rats to higher noise levels (97dB), but equally vulnerable to moderate levels (92dB). By contrast, the aged rats were virtually insensitive to 700ppm styrene compared to the young animals. Two additional studies were performed controlling and examining the influence of body weight and post-natal age on the sensitivity to styrene. Rats of the same age (21 weeks) and but having different body weight (∼310g versus ∼410g) did not show any difference of sensitivity to 700ppm styrene, whereas 14-week-old rats with the same body weight as 21-week-old rats (∼350g) revealed increased sensitivity to styrene. These results show that weight does not play a key role in the sensitivity to styrene, and suggest a long period of increased sensitivity to styrene during the first months of life.
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Affiliation(s)
- Benoît Pouyatos
- Institut National de Recherche et de Sécurité, Ave de Bourgogne, BP 27, 54501 Vandoeuvre, France
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Lichtenhan JT, Chertoff ME, Smittkamp SE, Durham D, Girod DA. Predicting severity of cochlear hair cell damage in adult chickens using DPOAE input-output functions. Hear Res 2005; 201:109-20. [PMID: 15721566 DOI: 10.1016/j.heares.2004.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2004] [Accepted: 09/06/2004] [Indexed: 11/15/2022]
Abstract
Distortion product otoacoustic emissions (DPOAE) were recorded from the ear canal of aged broiler chickens which have been shown to present with age-related cochlear degeneration [Hear. Res. 166 (2002) 82]. We describe the relationship between the shape of the DPOAE input-output (I/O) function and the type of hair cell damage present at and between the cochlear frequency places of the DPOAE primary tones (f1 and f2). The mid stimulus level compressive growth of the mean DPOAE I/O functions is reduced in a graded fashion relative to the severity of hair cell damage. However, individual DPOAE I/O functions within most hair cell damage groups show large variability from this characteristic. Various least squares regression models were used to predict hair cell density from indices derived from the DPOAE I/O function (area, threshold and slope). The results showed that no simple linear relationship exists between hair cell density and the DPOAE I/O function indices. Multivariate binary logistic regression used DPOAE I/O function indices to predict membership in hair cell damage groups. The logistic model revealed that DPOAE threshold can be used to predict the occurrence of severe/total hair cell damage with good specificity though poor sensitivity.
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Affiliation(s)
- Jeffery T Lichtenhan
- Department of Hearing and Speech, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
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Lapsley Miller JA, Marshall L, Heller LM. A longitudinal study of changes in evoked otoacoustic emissions and pure-tone thresholds as measured in a hearing conservation program. Int J Audiol 2004; 43:307-22. [PMID: 15457813 DOI: 10.1080/14992020400050040] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Non-linear transient-evoked otoacoustic emissions (TEOAEs) at 74dB pSPL, distortion-product otoacoustic emissions (DPOAEs) at 65/45dB SPL and pure-tone audiometry were used to detect noise-induced, inner car changes in a longitudinal study. Repeated-measures ANOVAs were made on the Noise (n=69) and Quiet (n=42) groups. The Noise group's hearing thresholds increased by 1.2 dB and DPOAE amplitude decreased by -0.9 dB. For both groups, TEOAE amplitude decreased by approximately -0.6 dB. Eight of 12 ears with permanent threshold shift (PTS) and 10 of 13 ears with temporary threshold shift (TTS) showed TEOAE decrements or low baseline TEOAE amplitudes. Fewer TTS and PTS ears also showed DPOAE decrements, and there was never a DPOAE decrement without a corresponding TEOAE decrement or low TEOAE baseline. Some TTS ears showed permanent emission decrements. Although otoacoustic emissions show promise in detecting noise-induced inner ear changes, it is premature to use them in hearing conservation programs.
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28
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Davis B, Qiu W, Hamernik RP. The use of distortion product otoacoustic emissions in the estimation of hearing and sensory cell loss in noise-damaged cochleas. Hear Res 2004; 187:12-24. [PMID: 14698083 DOI: 10.1016/s0378-5955(03)00339-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Distortion product otoacoustic emissions (DPOAE), permanent threshold shifts (PTS) and outer hair cell (OHC) losses were analyzed in a population of 187 noise-exposed chinchillas to determine the predictive accuracy (sensitivity and specificity) of the DPOAE for PTS and OHC loss. Auditory evoked potentials (AEP) recorded from the inferior colliculus of the brainstem were used to estimate hearing thresholds and surface preparation histology was used to determine sensory cell loss. The overlapping cumulative distributions and high variability in emission responses for both PTS and OHC loss made it difficult to predict AEP threshold and OHC loss from DPOAE level measurements alone. Using a strict criterion (i.e. emissions better than the 5th percentile of the preexposure DPOAE level, and PTS< or = 5 dB or OHC loss< or = 5%), it was found that the postexposure DPOAE level could be used with reasonable confidence to determine if the status of peripheral auditory system was either normal (i.e. PTS< or = 5 dB) or abnormal (PTS>30 dB or OHC loss>40%). However, the high variability of individual DPOAE responses resulted in a broad region of 'uncertainty' (i.e. 5<PTS< or = 30 dB and 5%<OHC loss< or = 40%) making it difficult in the chinchilla model to use the postexposure DPOAE level with confidence to predict in individual subjects the amount of PTS or OHC loss. Our results also indicate that significant reductions in the amplitude of the DPOAE are related primarily to a systematic loss of OHCs, and that a postexposure DPOAE level< or = 10 dB SPL, obtained with a low frequency primary level of 65 dB SPL, represents a criterion value which can serve as an indication of significant OHC loss (> or = 50%) or PTS (> or = 35 dB) in noise-exposed chinchillas. Based on an exponential regression analysis of individual subjects, correlations were higher for PTS/DPOAE than for OHC loss/DPOAE.
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Affiliation(s)
- Bob Davis
- Auditory Research Laboratory, Plattsburgh State University of New York, 107 Beaumont Hall, 101 Broad St., Plattsburgh, NY, 12901, USA.
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Fraenkel R, Freeman S, Sohmer H. Use of ABR threshold and OAEs in detection of noise induced hearing loss. J Basic Clin Physiol Pharmacol 2003; 14:95-118. [PMID: 14558726 DOI: 10.1515/jbcpp.2003.14.2.95] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
OBJECTIVE To determine which measure is the most sensitive to noise induced hearing loss (NIHL): auditory nerve brainstem response (ABR), distortion product otoacoustic emission (DPOAE) or transient evoked otoacoustic emission (TEOAE), and how to assess possible changes in these responses. SUBJECTS & METHODS Four groups of rats were exposed to various durations of 113 dB SPL broadband noise: 5 or 10 minutes (temporary changes in cochlear function), and 3 or 4 hours (permanent changes). Group means and data from individual animals were compared before and after exposure. RESULTS Mean group DPOAE amplitude reduction showed no clear advantage over mean ABR threshold elevation in detection of temporary and permanent NIHL. Data from individual rats, however, indicated a clinical advantage for DPOAEs in detecting slight temporary, but not permanent, changes. TEOAEs were more sensitive in detecting changes in individual rats than as a group measure. CONCLUSIONS TEOAE and DPOAE monitoring may improve detection of NIHL, though it should be used in conjunction with audiometric threshold monitoring.
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Affiliation(s)
- Rachel Fraenkel
- Department of Physiology, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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Harding GW, Bohne BA, Ahmad M. DPOAE level shifts and ABR threshold shifts compared to detailed analysis of histopathological damage from noise. Hear Res 2002; 174:158-71. [PMID: 12433407 DOI: 10.1016/s0378-5955(02)00653-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A detailed comparison of 2f(1)-f(2) distortion product otoacoustic emission (DPOAE) level shifts (LS) and auditory brainstem response (ABR) threshold shifts with noise-induced histopathology was conducted in chinchillas. DPOAE levels (i.e., L(1) and L(2)) at f(1) and f(2), respectively, ranged from 55-75 dB sound pressure level (SPL), with f(2)/f(1)=1.23, 6 points/octave, f(2)=0.41-20 kHz, and ABR thresholds at 0.5-20 kHz, 2 points/octave, were determined pre-exposure. The exposure was a 108 dB SPL octave band of noise centered at 4 kHz (1-1.75 h, n=6) or 80-86 dB SPL (24 h, n=5). DPOAE LSs (magnitude pre- minus post-exposure) and ABR threshold shifts (TS) were determined at 0 days and up to 28 days post-exposure. The cochleae were fixed, embedded in plastic and dissected into flat preparations. The length of the organ of Corti (OC) was measured; missing inner (IHC) and outer (OHC) hair cells counted; stereocilia damage rated; and regions of OC and nerve-fiber loss determined. Cytocochleograms were made showing functional loss and structural damage with the LS and TS overlaid. Some unexpected results were obtained. First, the best correlation of LS with histopathology required plotting the DPOAE data at f(1) with respect to the chinchilla-place map. The best correlation of TS was with IHC and nerve-fiber loss. Second, wide regions of up to 10% scattered OHC loss in the apical half of the OC showed little or no LS. Third, with the 108 dB SPL noise, there was 20-40 dB of recovery for DPOAEs at mid-high frequencies (3-10 kHz) in eight of 12 cochleae where there was 70-100% OHC loss in the basal half of the OC. The largest recovery at mid-high frequencies occurred in regions where the OC was entirely missing. Fourth, with the 80-86 dB SPL noise, there was no LS at small focal lesions (100% loss of OHCs over 0.4 mm) when the frequency place of either f(1) or f(2) was within the lesion but not both. There was no correlation of LS with OHC stereocilia loss, fusion or disarray. These results suggest that, after noise exposure, DPOAEs at mid-high frequencies can originate from or be augmented by generators located at someplace other than the frequency place of f(2), possibly the basal 20% of the OC when this region is intact. Also, noise-induced DPOAE LSs seemed to reflect differing mechanisms for temporary and permanent hearing loss.
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Affiliation(s)
- Gary W Harding
- Department of Otolaryngology, Box 8115, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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Abstract
The study was carried out to test whether or not cubic distortion otoacoustic emissions were more sensitive than auditory-evoked potentials for assessing styrene-induced hearing losses in the Long-Evans rat. For the purposes of comparison, changes in cubic distortion product otoacoustic emissions (DeltaDPOAE), evoked potential permanent threshold shifts (PTS) and outer hair cell losses were measured in a population of styrene-treated rats. Each rat was exposed to either 650 or 750 ppm of styrene for 4 weeks, 5 days per week, 6 h per day. Only the 750 ppm exposure caused significant hearing losses. For this concentration, DPOAEs appeared as sensitive to styrene as the audiometry performed with evoked potentials, but not more. A high coefficient of correlation [0.84< or =r< or =0.91] between DeltaDPOAE and PTS was obtained across the styrene-induced effects for frequencies ranging from 5 to 12 kHz. This experiment demonstrates that DPOAEs can be used to monitor the ototoxicity induced by styrene even though they cannot be considered as a more sensitive index of cochlear pathology than the evoked potentials, at least under our experimental conditions. Likewise evoked potentials, normal DPOAEs may not guarantee a normal cochlear status and therefore results of DPOAE measurements should be interpreted cautiously. The use of both techniques and the determination of the ratio DeltaDPOAE/PTS may be useful in determining the cause of hearing loss: mechanical or chemical process. Moreover, because of its non-invasive and objective characteristics, the use of DPOAEs could play a greater role in a prevention policy.
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Affiliation(s)
- Benoît Pouyatos
- Laboratoire de Neurotoxicité, Institut National de Recherche et de Sécurité, Avenue de Bourgogne, P.O. Box 27, 54501 Vandoeuvre, France
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Hamernik RP, Ahroon WA, Patterson JH, Qiu W. Relations among early postexposure noise-induced threshold shifts and permanent threshold shifts in the chinchilla. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2002; 111:320-326. [PMID: 11831804 DOI: 10.1121/1.1428545] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Threshold shifts (TS) were measured at various times following a wide variety of noise exposures on over 900 chinchillas. An analysis of postexposure TS measures and noise-induced permanent threshold shift (PTS) showed that, across audiometric test frequency, there was a consistent relation between these variables of the form PTS (dB) = alpha(e(TS/beta) - 1), where, for a given test frequency, alpha (dB) and beta (dB) are constants. TSs were measured immediately following exposure (TS0), 24 h after exposure (TS24), and at several intermediate times in order to estimate the maximum TS (TSmax). Correlation between TS and PTS at the various test frequencies was highest for TS24. An analysis of the 90th-percentile PTS showed a linear growth of PTS with TS24 of approximately 0.7 dB PTS/dB TS24. These data provide some support, in the chinchilla model, for a variation of the three postulates originally presented by Kryter et al. [J. Acoust. Soc. Am. 39, 451 (1966)]. Specifically: (i) TS24 is a consistent measure of the effects of a traumatic noise exposure. (ii) All exposures that produce a given TS24 will be equally hazardous. (iii) Noise-induced PTS in the most susceptible animals, following many years of exposure, is approximately equal to (0.7)TS24 measured after an 8-h exposure to the same noise.
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Affiliation(s)
- Roger P Hamernik
- Auditory Research Laboratory, State University of New York, Plattsburgh 12901, USA.
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Hamernik RP, Qiu W. Energy-independent factors influencing noise-induced hearing loss in the chinchilla model. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2001; 110:3163-3168. [PMID: 11785817 DOI: 10.1121/1.1414707] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effects on hearing and the sensory cell population of four continuous, non-Gaussian noise exposures each having an A-weighted L(eq)=100 dB SPL were compared to the effects of an energy-equivalent Gaussian noise. The non-Gaussian noise conditions were characterized by the statistical metric, kurtosis (beta), computed on the unfiltered, beta(t), and the filtered, beta(f), time-domain signals. The chinchilla (n=58) was used as the animal model. Hearing thresholds were estimated using auditory-evoked potentials (AEP) recorded from the inferior colliculus and sensory cell populations were obtained from surface preparation histology. Despite equivalent exposure energies, the four non-Gaussian conditions produced considerably greater hearing and sensory cell loss than did the Gaussian condition. The magnitude of this excess trauma produced by the non-Gaussian noise was dependent on the frequency content, but not on the average energy content of the impacts which gave the noise its non-Gaussian character. These results indicate that beta(t) is an appropriate index of the increased hazard of exposure to non-Gaussian noises and that beta(f) may be useful in the prediction of the place-specific additional outer hair cell loss produced by non-Gaussian exposures. The results also suggest that energy-based metrics, while necessary for the prediction of noise-induced hearing loss, are not sufficient.
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Affiliation(s)
- R P Hamernik
- Auditory Research Laboratory, State University of New York, Plattsburgh 12901, USA.
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