Technical Report: Distortion Product Otoacoustic Emissions That Are Not Outer Hair Cell Emissions

2009 ◽  
Vol 20 (05) ◽  
pp. 306-310
Author(s):  
Shlomo Silman ◽  
Michele B. Emmer ◽  
Carol A. Silverman

Purpose: To present a case study in order to alert clinicians to the possibility of occurrence of intermodulation distortion during otoacoustic emissions testing that arises from the cavity formed by the external auditory meatus and tympanic membrane rather than from the inner ear, compromising the reliability and validity of otoacoustic emissions testing. Research Design: Prospective case study. Study Sample: A young (26-year-old) female adult with a longstanding, bilateral, essentially moderate to severe sensorineural hearing loss presented with robust distortion product otoacoustic emissions. Results: Repeat otoacoustic emissions testing with another device of the same model revealed essentially absent distortion product otoacoustic emissions and transient otoacoustic emissions. Calibration of both otoacoustic emissions devices using a 1 cc membranous cavity indicated present intermodulation distortion for the device that yielded robust distortion product otoacoustic emissions for the patient but absent intermodulation distortion for the device that revealed absent distortion product otoacoustic emissions and absent transient evoked otoacoustic emissions for the patient. The calibration findings for the device yielding intermodulation distortion in the cavity were confirmed by an engineer of a technical instrumentation company. The device was shipped back to the manufacturer of the device for repair. The manufacturer's engineers diagnosed the problem as an interruption in the relay system. Following repair, calibration revealed the absence of intermodulation distortion in the 1 cc membranous cavity. Conclusions: The findings have implications for the reliability and validity of otoacoustic emissions. Clinicians should routinely calibrate otoacoustic emissions devices using 1.0 and 0.5 cc membranous cavities to rule out intermodulation distortion that could produce artifactual otoacoustic emissions in patients.

1998 ◽  
Vol 126 (1-2) ◽  
pp. 67-74 ◽  
Author(s):  
Gregory I Frolenkov ◽  
Inna A Belyantseva ◽  
Mauricio Kurc ◽  
Mary Ann Mastroianni ◽  
Bechara Kachar

2015 ◽  
Vol 129 (12) ◽  
pp. 1174-1181 ◽  
Author(s):  
N Wooles ◽  
M Mulheran ◽  
P Bray ◽  
M Brewster ◽  
A R Banerjee

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.


2019 ◽  
Vol 5 (3) ◽  
pp. 130-133
Author(s):  
Virender Singh ◽  
◽  
BS Rakesh ◽  
MB Bharathi ◽  
Kota Harish Nag ◽  
...  

Aim: To analyze the effect of acoustic and mechanical trauma of drilling on the outer hair cell function of the non operated ear using distortion-product otoacoustic emissions (DPOAE’s) after mastoidectomy and its relation with the duration of drilling, age, and gender of the patient along with duration and permanency of the effects. Study Design: Observational study. Materials and Methods: Screening DPOAE’s were recorded preoperatively, immediate postoperative period, one hour postoperatively, 1st and 7th postoperative days in the normal ear in 94 patients who underwent tympanomastoidectomy for unilateral chronic suppurative otitis media (CSOM). DPOAE’s were measured using Neuro-audio-screener (Neurosoft Inc.) at 1.5 KHz, 2.1 KHz, 3.3 KHz, and 4.2 KHz. If DPOAE’s were absent preoperatively, the patients were not evaluated further and patients who had absent DPOAE’s post-operatively were successively followed till DPOAE’s were regained. Results: Of the 94 patients included, in 62 patients DPOAE’s were present preoperatively. Out of these 62, in 30 patients DPOAE’s were absent immediate postoperatively. On repeat testing, DPOAE’s were absent in 20 patients after 1 hour and in 8 patients after 1 day. On re-evaluation of these 8 patients after 1 week all of them had regained the DPOAE’s. In terms of duration of drilling, 66.6% patients in immediate post operative period, 90% patients in 1-hour post operative and 100 % patients on post operative day 1, having absent DPOAE’s had drilling time more than 60 minutes. Patients more than 30 years of age are affected more, but there is no preponderance for any gender. Conclusion: Nonoperated ear does have the effect of acoustic and mechanical trauma by vibration transmitted from another side during drilling of the operative ear mastoid bone. This effect is temporary and depends on the duration of drilling also.


2021 ◽  
pp. 1-16
Author(s):  
Naomi F. Bramhall ◽  
Garnett P. McMillan ◽  
Amy N. Mashburn

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


1997 ◽  
Vol 116 (6) ◽  
pp. 585-592 ◽  
Author(s):  
Kathleen C. Y. Sie ◽  
Susan J. Norton

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.


Author(s):  
Lucretia Petersen ◽  
Wayne J. Wilson ◽  
Harsha Kathard

Background: Although distortion product otoacoustic emissions (DPOAEs) are useful in evaluating cochlear outer hair cell function, determining the optimal stimulus parameters could result in a more reliable, sensitive and specific diagnostic tool across the range of DPOAE applications. Objectives: To identify which stimulus parameters warrant further investigation for eliciting the largest and most reliable DPOAEs in adult humans. Method: A single group, repeated measures design involving a convenience sample of 20 normal-hearing participants between 19 and 24 years of age. Results: Descriptive statistics and mixed model analyses suggested L1/L2 intensity levels of 65/65 dB sound pressure level (SPL) and 65/55 dB SPL, and f2/f1 ratios of 1.18, 1.20 and 1.22 elicited larger and more reliable DPOAEs in both ears. Conclusion: Further investigation of the 65/65 dB SPL and 65/55 dB SPL intensity levels and the 1.18, 1.20 and 1.22 f2/f1 ratios is warranted to determine the stimulus parameters for eliciting the largest and most reliable DPOAEs in adult humans across the range of DPOAE applications.


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