scholarly journals Input-output functions of the nonlinear-distortion component of distortion-product otoacoustic emissions in normal and hearing-impaired human ears

2017 ◽  
Vol 141 (5) ◽  
pp. 3203-3219 ◽  
Author(s):  
Dennis Zelle ◽  
Lisa Lorenz ◽  
John P. Thiericke ◽  
Anthony W. Gummer ◽  
Ernst Dalhoff
2005 ◽  
Vol 48 (5) ◽  
pp. 1165-1186 ◽  
Author(s):  
Tracy S. Fitzgerald ◽  
Beth A. Prieve

Although many distortion-product otoacoustic emissions (DPOAEs) may be measured in the ear canal in response to 2 pure tone stimuli, the majority of clinical studies have focused exclusively on the DPOAE at the frequency 2f1-f2. This study investigated another DPOAE, 2f2-f1, in an attempt to determine the following: (a) the optimal stimulus parameters for its clinical measurement and (b) its utility in differentiating between normal-hearing and hearing-impaired ears at low-to-mid frequencies (≤2000 Hz) when measured either alone or in conjunction with the 2f1-f2 DPOAE. Two experiments were conducted. In Experiment 1, the effects of primary level, level separation, and frequency separation (f2/f1) on 2f2-f1 DPOAE level were evaluated in normal-hearing ears for low-to-mid f2 frequencies (700–2000 Hz). Moderately high-level primaries (60–70 dB SPL) presented at equal levels or with f2 slightly higher than f1 produced the highest 2f2-f1 DPOAE levels. When the f2/f1 ratio that produced the highest 2f2-f1 DPOAE levels was examined across participants, the mean optimal f2/f1 ratio across f2 frequencies and primary level separations was 1.08. In Experiment 2, the accuracy with which DPOAE level or signal-to-noise ratio identified hearing status at the f2 frequency as normal or impaired was evaluated using clinical decision analysis. The 2f2-f1 and 2f1-f2 DPOAEs were measured from both normal-hearing and hearing-impaired ears using 2 sets of stimulus parameters: (a) the traditional parameters for measuring the 2f1-f2 DPOAE (f2/f1 = 1.22; L1, L2 = 65, 55 dB SPL) and (b) the new parameters that were deemed optimal for the 2f2-f1 DPOAE in Experiment 1 (f2/f1 = 1.073, L1 and L2 = 65 dB SPL). Identification of hearing status using 2f2-f1 DPOAE level and signal-to-noise ratio was more accurate when the new stimulus parameters were used compared with the results achieved when the 2f2-f1 DPOAE was recorded using the traditional parameters. However, identification of hearing status was less accurate for the 2f2-f1 DPOAE measured using the new parameters than for the 2f1-f2 DPOAE measured using the traditional parameters. No statistically significant improvements in test performance were achieved when the information from the 2 DPOAEs was combined, either by summing the DPOAE levels or by using logistic regression analysis.


1997 ◽  
Vol 100 (4) ◽  
pp. 436-443 ◽  
Author(s):  
Eiji Chida ◽  
Nobukiyo Satoh ◽  
Mitsugu Kawanami ◽  
Masaaki Kashiwamura ◽  
Tohru Sakamoto ◽  
...  

Author(s):  
Hend F. Alshabory ◽  
Takwa A. Gabr ◽  
Mona A. Kotait

Abstract Introduction Tinnitus is the perception of sound in the absence of external sound stimulation. There is a general agreement that it is a direct consequence of irreversible and permanent cochlear damage. Objectives The present work is designed to study the distortion product otoacoustic emissions (DPOAEs) in tinnitus patients with normal hearing in comparison with normal hearing control and to study any possible correlation between DPOAEs recording and patients' complaints. Methods The present study included 80 subjects divided into 2 groups: Control group: consisted of 30 normal-hearing adults not complaining of tinnitus and Study group: consisted of 50 normal-hearing adults complaining of tinnitus. The methodology includes full audiological history, otoscopic examination, basic audiological evaluation, DPOAEs including both DP-gram and DPOAEs input/output functions. Results Basic audiological evaluation showed within normal hearing sensitivity in both groups, however, with significant higher hearing thresholds in tinnitus patients at all frequency ranges. The Tinnitus Handicap Inventory Questionnaire showed mean scores of 35.2 ± 16.9 in the study group. The DP-gram showed higher amplitudes in the control group when compared with tinnitus patients. The DPOAEs input-output functions at different frequencies (1, 2, 4 and 6kHz) also showed higher amplitudes at all frequencies and different input levels. The slope of the I/O function tends to be steeper in tinnitus cases. Conclusion Patients with tinnitus might have neural dysfunction at either the level of the cochlea, as shown in reduced DPOAE levels, and changes in the normal DP-I/O function recorded in the present work.


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