Conditioning-Related Protection From Acoustic Injury: Effects of Chronic Deefferentation and Sham Surgery

1997 ◽  
Vol 78 (6) ◽  
pp. 3095-3106 ◽  
Author(s):  
Sharon G. Kujawa ◽  
M. Charles Liberman
Keyword(s):  
Brain Stem ◽  
Otoacoustic Emissions ◽  
Noise Exposure ◽  
Outer Hair Cell ◽  
Acoustic Stimulus ◽  
Cell Region ◽  
Distortion Product ◽  
Traumatic Exposure ◽  
Sham Surgery ◽  
Conditioning Treatment

Kujawa, Sharon G. and M. Charles Liberman. Conditioning-related protection from acoustic injury: effects of chronic deefferentation and sham surgery. J. Neurophysiol. 78: 3095–3106, 1997. The inner ear can be made less vulnerable to acoustic injury by a “conditioning” treatment involving exposure to a moderate-level acoustic stimulus before the acoustic overexposure. The present study was designed to explore the role of the olivocochlear (OC) system in this “protection.” Guinea pigs were divided into a number of groups: some (trauma-only) were exposed to a traumatic noise for 4 h at 109 dB SPL; others (condition/trauma) were conditioned by daily exposure to the same noise at 85 dB SPL before the traumatic exposure. In OC-intact animals, the condition/trauma group showed significantly less permanent threshold shift (PTS) than the trauma-only group as measured via compound action potentials and distortion-product otoacoustic emissions (DPOAEs). Other animals with identical noise-exposure regimens underwent deefferentation surgery before the start of conditioning: the OC bundle (OCB) was cut in the brain stem, either at the midline (cutting the crossed OCB to both ears) or at the sulcus limitans (cutting all OC fibers to 1 side). Lesion success was quantified by measuring OC fascicles to the outer hair cell region in each ear. The results from the surgical groups showed that total loss of the OCB significantly increased the noise-induced PTS, whereas loss of the COCB only did not; that the conditioning exposure in deefferented animals increased, rather than decreased, the PTS from the traumatic exposure; and that animals undergoing sham surgery (brain stem cuts that failed to transect the OCB) appeared protected whether or not they received the conditioning noise exposure. The latter result suggests that conditioning-related protection may arise from a generalized stress response, which can be elicited by noise exposure, brain surgery, or a variety of other means. The former results make an OC role in the conditioning process, per se, difficult to assess, given the large effects of OC activity on general acoustic vulnerability.

Protection against Noise Trauma by Sound Conditioning

1997 ◽  
Vol 76 (4) ◽  
pp. 248-255 ◽  
Author(s):  
Barbara Canlon
Keyword(s):  
Otoacoustic Emissions ◽  
Outer Hair Cell ◽  
Human Subjects ◽  
Acoustic Stimulus ◽  
Conditioning Stimulus ◽  
Outer Hair Cells ◽  
Noise Trauma ◽  
Distortion Product ◽  
Underlying Mechanisms ◽  
X 24

Sound conditioning provides protection against a subsequent noise trauma. The sound conditioning paradigm consists of a low-level, long-term, non-damaging acoustic stimulus (1 kHz, 81 dB SPL x 24 days). Morphological and physiological alterations are not induced by the sound conditioning stimulus alone. In addition, the middle ear muscles have been shown not to be influenced by sound conditioning. It has been shown that after exposure to a traumatic stimulus, sound conditioning protects the outer hair cell morphology (fewer missing outer hair cells), as well as physiology (distortion product otoacoustic emissions) compared to an unconditioned group exposed only to the traumatic stimulus. Further studies are needed in order to establish the underlying mechanisms for the phenomenon of sound conditioning. Nevertheless, since sound-conditioning experiments have been successfully applied to human subjects our understanding of hearing impaired individuals has been enhanced.

Comparison of distortion product otoacoustic emissions and pure tone audiometry in occupational screening for auditory deficit due to noise exposure

2015 ◽  
Vol 129 (12) ◽  
pp. 1174-1181 ◽  
Author(s):  
N Wooles ◽  
M Mulheran ◽  
P Bray ◽  
M Brewster ◽  
A R Banerjee
Keyword(s):  
Otoacoustic Emissions ◽  
Pure Tone ◽  
Noise Exposure ◽  
Outer Hair Cell ◽  
Cell Function ◽  
Pure Tone Audiometry ◽  
Otoacoustic Emission ◽  
Distortion Product Otoacoustic Emissions ◽  
Distortion Product Otoacoustic Emission ◽  
Distortion Product

AbstractObjective:To examine whether distortion product otoacoustic emissions can serve as a replacement for pure tone audiometry in longitudinal screening for occupational noise exposure related auditory deficit.Methods:A retrospective review was conducted of pure tone audiometry and distortion product otoacoustic emission data obtained sequentially during mandatory screening of brickyard workers (n = 16). Individual pure tone audiometry thresholds were compared with distortion product otoacoustic emission amplitudes, and a correlation of these measurements was conducted.Results:Pure tone audiometry threshold elevation was identified in 13 out of 16 workers. When distortion product otoacoustic emission amplitudes were compared with pure tone audiometry thresholds at matched frequencies, no evidence of a robust relationship was apparent. Seven out of 16 workers had substantial distortion product otoacoustic emissions with elevated pure tone audiometry thresholds.Conclusion:No clinically relevant predictive relationship between distortion product otoacoustic emission amplitude and pure tone audiometry threshold was apparent. These results do not support the replacement of pure tone audiometry with distortion product otoacoustic emissions in screening. Distortion product otoacoustic emissions at frequencies associated with elevated pure tone audiometry thresholds are evidence of intact outer hair cell function, suggesting that sites distinct from these contribute to auditory deficit following ototrauma.

scholarly journals Subclinical Auditory Dysfunction: Relationship Between Distortion Product Otoacoustic Emissions and the Audiogram

2021 ◽  
pp. 1-16
Author(s):  
Naomi F. Bramhall ◽  
Garnett P. McMillan ◽  
Amy N. Mashburn
Keyword(s):  
Otoacoustic Emissions ◽  
Pure Tone ◽  
Noise Exposure ◽  
Outer Hair Cell ◽  
Self Report ◽  
Distortion Product Otoacoustic Emissions ◽  
Sample Mean ◽  
Distortion Product ◽  
Clinically Normal ◽  
Auditory Physiology

Purpose Distortion product otoacoustic emissions (DPOAEs) and audiometric thresholds have been used to account for the impacts of subclinical outer hair cell (OHC) dysfunction on auditory perception and measures of auditory physiology. However, the relationship between DPOAEs and the audiogram is unclear. This study investigated this relationship by determining how well DPOAE levels can predict the audiogram among individuals with clinically normal hearing. Additionally, the impacts of age, noise exposure, and the perception of tinnitus on the ability of DPOAE levels to predict the audiogram were evaluated. Method Suprathreshold DPOAE levels from 1 to 10 kHz and pure-tone thresholds from 0.25 to 16 kHz were measured in 366 ears from 194 young adults (19–35 years old) with clinically normal audiograms and middle ear function. The measured DPOAE levels at all frequencies were used to predict pure-tone thresholds at each frequency. Participants were grouped by age, self-reported noise exposure/Veteran status, and self-report of tinnitus. Results Including DPOAE levels in the pure-tone threshold prediction model improved threshold predictions at all frequencies from 0.25 to 16 kHz compared with a model based only on sample mean pure-tone thresholds, but these improvements were modest. DPOAE levels for f 2 frequencies of 4 and 5 kHz were particularly influential in predicting pure-tone thresholds above 4 kHz. However, prediction accuracy varied based on participant characteristics. On average, predicted pure-tone thresholds were better than measured thresholds among Veterans, individuals with tinnitus, and the oldest age group. Conclusions These results indicate a complex relationship between DPOAE levels and the audiogram. Underestimation of pure-tone thresholds for some groups suggests that additional factors other than OHC damage may impact thresholds among individuals within these categories. These findings suggest that DPOAE levels and pure-tone thresholds may differ in terms of how well they reflect subclinical OHC dysfunction. Supplemental Material https://doi.org/10.23641/asha.13564745

Changes in Otoacoustic Emissions and Auditory Brain Stem Response after C/s-Platinum Exposure in Gerbils

1997 ◽  
Vol 116 (6) ◽  
pp. 585-592 ◽  
Author(s):  
Kathleen C. Y. Sie ◽  
Susan J. Norton
Keyword(s):  
Hearing Loss ◽  
Brain Stem ◽  
Otoacoustic Emissions ◽  
Outer Hair Cell ◽  
Outer Hair Cells ◽  
Distortion Product Otoacoustic Emissions ◽  
Auditory Brain Stem Response ◽  
Distortion Product ◽  
Auditory Brain Stem ◽  
Significant Difference

Ototoxicity associated with cis-platinum administration commonly presents as hearing loss and tinnitus. The hearing loss is usually an irreversible, high-frequency sensorineural loss. Histologic studies in humans and animals suggest that the outer hair cells (OHCs) are most susceptible to cis-platinum. Evoked otoacoustic emissions (EOAE), as a measure of outer hair cell function, are potentially useful in following ototoxic insults involving OHCs. Distortion-product otoacoustic emissions (DPOAE) test frequency-specific regions of the cochlea and therefore may be particularly well suited for monitoring ototoxic injuries. We measured distortion product otoacoustic emissions, at f2 = 2, 4, 6, 8, 10, and 12 kHz, in gerbils after a single large dose of cis-platinum. Animals treated with saline served as controls. The findings were compared to auditory brain stem evoked response (ABR) thresholds, using tone pips of the same frequencies. The DPOAE and ABR thresholds were measured before treatment and again 2, 5, and 14 days after drug administration. The changes in DPOAE were compared with the changes in ABR. No treatment effect was noted in the 2-day group. Animals treated with c/s-platinum demonstrated significant elevation of DPOAE and ABR thresholds compared with control animals at 5 and 14 days. There was no significant difference between the threshold changes in the 5-and 14-day groups.

Vocal Performance Teachers and Hearing Loss

2015 ◽  
Vol 16 (1) ◽  
pp. 15-24
Author(s):  
Vance Gunnell ◽  
Jeff Larsen
Keyword(s):  
Hearing Loss ◽  
Otoacoustic Emissions ◽  
Noise Exposure ◽  
Vocal Performance ◽  
Occupational Noise ◽  
Hearing Conservation ◽  
Occupational Noise Exposure ◽  
Distortion Product ◽  
Hearing Thresholds ◽  
Performance Teachers

Hearing thresholds and distortion product otoacoustic emissions were measured for teachers of vocal performance who were gathered for a national conference. Results showed mean audiometric thresholds to be consistent with noise induced hearing loss, more than what would be expected with normal aging. Years of instruction and age were considered as factors in the hearing loss observed. It was concluded that hearing conservation should be initiated with this group to help raise awareness and protect them from hearing loss due to occupational noise exposure.

Evaluating cochlear function and the effects of noise exposure in the B6.CAST+Ahl mouse with distortion product otoacoustic emissions

2004 ◽  
Vol 194 (1-2) ◽  
pp. 87-96 ◽  
Author(s):  
Ana E Vázquez ◽  
Ana M Jimenez ◽  
Glen K Martin ◽  
Anne E Luebke ◽  
Brenda L Lonsbury-Martin
Keyword(s):  
Otoacoustic Emissions ◽  
Noise Exposure ◽  
Distortion Product Otoacoustic Emissions ◽  
Cochlear Function ◽  
Distortion Product

Early Evidence of Cochlear Damage in a Large Sample of Percussionists

2005 ◽  
Vol 20 (3) ◽  
pp. 135-139
Author(s):  
Jodee A Pride ◽  
David R Cunningham
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Otoacoustic Emissions ◽  
Outer Hair Cell ◽  
Cell Damage ◽  
Normal Hearing ◽  
Outer Hair Cells ◽  
Sensory Loss ◽  
Distortion Product ◽  
Hair Cell Damage

Percussionists can be exposed to intermittent sound stimuli that exceed 145 dB SPL, although damage may occur to the outer hair cells at levels of 120 dB SPL. The present study measured distortion-product otoacoustic emissions (DPOAEs) in a group of 86 normal-hearing percussionists and 39 normal-hearing nonpercussionists. Results indicate that normal-hearing percussionists have lower DPOAE amplitudes than normal-hearing nonpercussionists. DPOAE amplitudes were significantly lower at 6000 Hz in both the left and right ears for percussionists. Percussionists also more frequently had absent DPOAEs, with the greatest differences occurring at 6000 Hz (absent DPOAEs in 25% of percussionists vs 10% of nonpercussionists). When all frequencies are considered as a group, 33% of the percussionists had an absent DPOAE in either ear at some frequency, compared to only 23% of the nonpercussionists. Otoacoustic emissions are more sensitive to outer hair cell damage than pure-tone threshold measurements and can serve as an important measurement of sensory loss (i.e., outer hair cell damage) in musicians before the person perceives the hearing loss. DPOAE monitoring for musicians, along with appropriate education and intervention, might help prevent or minimize music-induced hearing loss.

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