[Comparison of methods for early detection of noise vulnerability of the inner ear. Amplitude reduction of otoacoustic emissions are most sensitive at submaximal noise impulse exposure].
Noise-induced temporary impairment of cochlear function was measured with several audiometric tests in order to evaluate which method best predicts a vulnerable cochlea. We tested 10 normally-hearing and 13 subjects who were positive for temporary threshold shifts (TTS). The latter were selected from 194 soldiers who demonstrated a TTS higher than 15 dB after regular training with firearms. Acoustic distortion products (DPOAE), click-evoked otoacoustic emissions (TEOAE), upper limit of hearing (ULH) and pure-tone and high-frequency audiometry were used to evaluate possible increased vulnerability of the cochlea. Tests were conducted at lower sound intensities (white noise, 90 dB SPL, 5 min; impact noise, 100 or 106 dB SPLs, 10 impulses/s, 5 min). Seventy per cent of the TTS-positive soldiers studied exhibited significant reductions of TEOAE amplitudes, whereas a stable emission was observed in all control subjects. DPOAE alterations were seen in 38% of the soldiers tested. These results indicate that TEOAE is the most sensitive, objective method for detecting a positive disturbance in cochlear function. Although the upper limit of hearing was also a very sensitive method, variability of this psychoacoustic method depended on the help and experience of the subjects being tested.
Plinkert
P K
PK
Universitäts-HNO-Klinik Tübingen.
Hemmert
W
W
Zenner
H P
HP
D000328:Adult; D001301:Audiometry, Pure-Tone; D001305:Auditory Fatigue / Q000502:physiology*; D003051:Cochlea / Q000503:physiopathology; D005260:Female; D005389:Firearms; D018072:Hair Cells, Auditory, Outer / Q000503:physiopathology; D006316:Hearing Loss, High-Frequency / Q000503:physiopathology / Q000517:prevention & control; D006317:Hearing Loss, Noise-Induced / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D008144:Loudness Perception / Q000502:physiology; D008297:Male; D008403:Mass Screening; D008889:Military Personnel; D009784:Occupational Diseases / Q000503:physiopathology / Q000517:prevention & control*; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D010898:Pitch Perception / Q000502:physiology; D012307:Risk Factors
Methodenvergleich zur Früherkennung einer Lärm-vulnerabilität des Innenohres. Amplitudenreduktion otoakustischer Emissionen am empfindlichsten bei subriskanter Impulsschallreizung.