DPOAE-Grams in Patients with Acute Tonal Tinnitus

2005 ◽  
Vol 132 (4) ◽  
pp. 550-553 ◽  
Author(s):  
Haralampos Gouveris ◽  
Jan Maurer ◽  
Wolf Mann

OBJECTIVE: To investigate cochlear outer hair cell function in patients with acute tonal tinnitus and normal or near-normal hearing threshold. STUDY DESIGN AND SETTING: Prospective controlled study in an academic tertiary health center. Distortion products of otoacoustic emissions (DPOAE)-grams of 32 ears with acute tonal tinnitus and normal hearing or minimal hearing loss were compared with those of 17 healthy nontinnitus ears. RESULTS: Tinnitus ears exhibited relatively increased amplitudes of DPOAE at high frequencies (4-6.3 kHz) when compared with the group of healthy ears and relatively decreased DPOAE amplitudes at middle frequencies (1650-2400 Hz). Statistically significant ( P < 0.01) increased mean values of DPOAE amplitudes were observed only at a frequency of f2 equal to 4.9 kHz. CONCLUSIONS AND SIGNIFICANCE: These findings suggest an altered functional state of the outer hair cells at a selected high-frequency region of the cochlea in ears with acute tonal tinnitus and normal or near-normal hearing threshold.

2005 ◽  
Vol 20 (3) ◽  
pp. 135-139
Author(s):  
Jodee A Pride ◽  
David R Cunningham

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.


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.


2013 ◽  
Vol 22 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Fatima T. Husain

Purpose The aim of this study was to measure the effect of tinnitus, while accounting for the effect of hearing loss and aging, on distortion product otoacoustic emissions (DPOAEs). Method DPOAEs were measured twice in both ears in 5 groups of participants: young adults with normal hearing, middle-age adults with normal hearing, adults with high-frequency sensorineural hearing loss, age-matched adults with similar hearing loss and tinnitus, and adults with normal hearing and chronic tinnitus. Results Multivariate analysis revealed a main effect of hearing loss and age, but no effect of tinnitus, across all 5 groups. Separate tests revealed significant effects of age and tinnitus in the normal-hearing groups and hearing loss in adults with or without tinnitus, but no effect of tinnitus in those with hearing loss. Conclusion DPOAE levels in the group of adults with hearing loss and tinnitus were diminished, but those in the group with normal hearing and tinnitus were enhanced, relative to DPOAE levels in the controls. Outer hair cell function, as indexed by DPOAEs, exhibits a complex association with tinnitus, and this has implications in the use of DPOAEs as a tool both for testing for tinnitus presence and for creating a model of neural mechanisms underlying tinnitus.


2021 ◽  
Author(s):  
Michael C. Stankewich ◽  
Jun-Ping Bai ◽  
Paul R. Stabach ◽  
Saaim Khan ◽  
Lei Song ◽  
...  

ABSTRACTReports have proposed a putative role for βV spectrin in outer hair cells (OHCs) of the cochlea. In an ongoing investigation of the role of the cytoskeleton in electromotility, we tested mice with a targeted exon deletion of βV spectrin (Spnb5), and unexpectedly find that Spnb5(-/-) animals’ auditory thresholds are unaffected. Similarly, these mice have normal OHC electromechanical activity (otoacoustic emissions) and non-linear capacitance. Moreover, Spnb5 mRNA is undetectable in the organ of Corti or OHCs. In contrast, magnitudes of auditory brainstem response (ABR) peak 1-amplitudes are significantly reduced. Evidence of a synaptopathy was absent with normal hair cell CtBP-2 counts. In Spnb5(-/-) mice, the number of afferent and efferent nerve fibers is decreased. Taken together, these data establish that βV spectrin is important for hearing, affecting neuronal structure and function. Significantly, these data exclude βV spectrin as functionally important to OHCs as has been previously suggested.


1997 ◽  
Vol 76 (4) ◽  
pp. 248-255 ◽  
Author(s):  
Barbara Canlon

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.


2007 ◽  
Vol 97 (4) ◽  
pp. 2930-2936 ◽  
Author(s):  
Stéphane F. Maison ◽  
Lisan L. Parker ◽  
Lucy Young ◽  
John P. Adelman ◽  
Jian Zuo ◽  
...  

Cochlear hair cells express SK2, a small-conductance Ca2+-activated K+ channel thought to act in concert with Ca2+-permeable nicotinic acetylcholine receptors (nAChRs) α9 and α10 in mediating suppressive effects of the olivocochlear efferent innervation. To probe the in vivo role of SK2 channels in hearing, we examined gene expression, cochlear function, efferent suppression, and noise vulnerability in mice overexpressing SK2 channels. Cochlear thresholds, as measured by auditory brain stem responses and otoacoustic emissions, were normal in overexpressers as was overall cochlear morphology and the size, number, and distribution of efferent terminals on outer hair cells. Cochlear expression levels of SK2 channels were elevated eightfold without striking changes in other SK channels or in the α9/α10 nAChRs. Shock-evoked efferent suppression of cochlear responses was significantly enhanced in overexpresser mice as seen previously in α9 overexpresser mice; however, in contrast to α9 overexpressers, SK2 overexpressers were not protected from acoustic injury. Results suggest that efferent-mediated cochlear protection is mediated by other downstream effects of ACh-mediated Ca2+ entry different from those involving SK2-mediated hyperpolarization and the associated reduction in outer hair cell electromotility.


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.


2016 ◽  
Vol 879 ◽  
pp. 2355-2360
Author(s):  
Arturo Moleti ◽  
Renata Sisto ◽  
Filippo Sanjust ◽  
Teresa Botti ◽  
Sandro Gentili

Otoacoustic emissions are a by-product of the active nonlinear amplification mechanism located in the cochlear outer hair cells, which provides high sensitivity and frequency resolution to human hearing. Being intrinsically sensitive to hearing loss at a cochlear level, they represent a promising non-invasive, fast, and objective diagnostic tool. On the other hand, the complexity of their linear and nonlinear generation mechanisms and other confounding physical phenomena (e.g., interference between different otoacoustic components, acoustical resonances in the ear canal, transmission of the middle ear) introduce a large inter-subject variability in their measured levels, which makes it difficult using them as a direct measure of the hearing threshold using commercially available devices. Nonlinear cochlear modeling has been successfully used to understand the complexity of the otoacoustic generation mechanisms, and to design new acquisition and analysis techniques that help disentangling the different components of the otoacoustic response, therefore improving the correlation between measured otoacoustic levels and audiometric thresholds. In particular, nonlinear cochlear modeling was able to effectively describe the complex (amplitude and phase) response of the basilar membrane, and the generation of otoacoustic emissions by two mechanisms, nonlinear distortion and linear reflection by cochlear roughness. Different phase-frequency relations are predicted for the otoacoustic components generated by the two mechanisms, so they can be effectively separated according to their different phase-gradient delay, using an innovative time-frequency domain filtering technique based on the wavelet transform. A brief introduction to these topics and some new theoretical and experimental results are presented and discussed in this study.


2002 ◽  
Vol 111 (5_suppl) ◽  
pp. 29-31 ◽  
Author(s):  
Yvonne S. Sininger ◽  
Patricia Trautwein

Auditory neuropathy (AN) is a term used to describe an auditory disorder in which there is evidence of normal outer hair cell function (otoacoustic emissions and/or cochlear microphonics) and poor function of the auditory nerve (absent or highly distorted auditory brain stem response starting with wave I). Many of these patients have evidence of generalized peripheral nerve disease, leading to an assumption that the peripheral portion of the auditory nerve is the most likely site of lesion. A small group of these patients has received cochlear implants, and the majority of them achieve average to above-average performance. Although this outcome may seem incongruous with neural disease, average performance by patients with AN may be a result of the reintroduction of neural synchrony by electrical stimulation and/or the fact that most deaf patients have poor nerve survival. Although cochlear implants are promising for deaf patients with AN, more study of the disorder is needed.


Author(s):  
Leticia Acle-Cervera ◽  
Javier Gavilanes-Plasencia ◽  
Beatriz Delgado-Vargas ◽  
Lorena Sánz-López ◽  
Mireya Bonet-Loscertales ◽  
...  

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