Analysis of distortion product otoacoustic emission spectra in normal-hearing adults.
OBJECTIVE
To evaluate the ability of distortion product otoacoustic emission (DPOAE) spectral characteristics to distinguish between ears with variable hearing sensitivity within the normal range.


METHODS
Distortion product grams (DP-grams) were acquired with primary tones decremented in 1/8-octave steps and primary-tone levels presented at 65 dB SPL (L1) and 45 dB SPL (L2) across an f2 frequency range of 842-7996 Hz from 22 normal-hearing adults (44 ears). Hearing thresholds of ears classified in Group A (n = 22) were better than ears classified in Group B (n = 22). Examined parameters of the DP-grams included spectral peak occurrence, peak height, peak width, and DPOAE levels. Analyses of variance were conducted to determine whether DP-gram parameters differed between Group A and Group B.


RESULTS
For the low-resolution DP-grams examined in this study, no significant between-group differences in peak occurrence, peak height, and peak width were observed. DPOAE levels were significantly higher in ears classified in Group A compared with ears classified in Group B in individuals with symmetrical hearing.


CONCLUSIONS
Although spectral peaks are evident in DP-grams acquired with low resolution of the primary tones, DPOAE levels are more effective in distinguishing ears with greater hearing sensitivity from less sensitive ears.
Bhagat
Shaum
S
The University of Memphis - School of Audiology and Speech-Language Pathology, 807 Jefferson Avenue, Memphis, TN 38015, USA. sbhagat@memphis.edu
D000328:Adult; D001309:Auditory Threshold; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D012984:Software; D055815:Young Adult