[Utility and limitations of speech audiometry testing in the detection of occupational noise-induced hearing loss: a comparative study in two groups in the hospital setting].
OBJECTIVE
The objective of this study is the evaluation of the calculation of 100% intelligibility threshold and noise resistance index as a monitoring test in populations exposed to noise in their work environment.


METHODS
This is a retrospective exposed-unexposed study as the exposure to the risk factors took place before the survey. The exposed subjects were chosen in principle on sonometric criteria and the unexposed subjects among employees whom we believe were not exposed. The exploration method included history taking, clinical examination, free field audiometry and speech audiometry with background noise.


RESULTS
The exposed population has a 100% intelligibility threshold on average equal to 29.69 dB, significantly higher than in the unexposed population where it is calculated at 25.30 dB (p = 0.07). The noise resistance index varies with age (p = 0.04).


CONCLUSIONS
Our study shows the existence of a significant hearing difference between two populations with different noise exposure. It demonstrates a relationship between a hearing loss risk factor such as noise and the occurrence of the "professional hearing loss" disorder. The calculation of the 100% intelligibility index and the noise resistance index advantageously complements tonal audiometry. These procedures provide a better approach to the social impact of hearing loss but were not useful in the detection of hearing loss.
CHU de Caen, Service ORL et de Chirurgie Cervico-Faciale, avenue de la Côte de Nacre, F-14033 Caen, France. babin-e@chu-caen.fr
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E
Babin
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A
Bequignon
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M
Goullet de Rugy
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E
Edy
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Moreau
J P
JP
Izard
A
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Valdazo
D000328:Adult; D001299:Audiometry / Q000379:methods*; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013060:Speech; D013065:Speech Intelligibility