Exposição ao ruído ocupacional: alterações no exame de emissões otoacústicas

Abstract

Exposure to occupational noise may cause injuries to the inner ear, and the distortion product otoacoustic emissions (DPOAE) may identify initial auditory alterations, thus assisting NIHL early diagnosis. Aim: The goal of this study was to evaluate DPOAE as a method to diagnose early physiopathological alterations caused by occupational noise exposure. Study Design: Transversal. Methods: 74 workers of the University of São Paulo, in the capital city of the State, participated in this investigation. They were divided in two age-matched groups and with tonal audiometric values within the acceptable limits: 37 were exposed to occupational noise and 37 were not exposed. Results: Risk estimates (Odds Ratio) of absent DPOAE was 12 fold higher for the group exposed to occupational noise (CI 95% 3.1 -45.9), in the frequencies of 3. 4 and 6 kHz. Conclusions: DPOAE may be useful in the identification of physiopathological hearing alterations caused by exposure to occupational noise, even in individuals with tonal audiometric responses within acceptable limits.

Avaliação audiológica em funcionários de um hospital público expostos a ruído

“…As for the 6kHz, it was the only frequency that showed an amplitude average construed as altered in both groups. Such findings match those of the studies that had recorded that the individuals subjected to noise, even within the thresholds of the normality standard, displayed lesser amplitude in the DPOAEor even the absence of one or more tested frequencies, when compared with the control group 10,11 . The fact that the current research refrains to portray the statistically significant difference when comparing the performance of both groups in the 4kHz frequency in the TEOAE test and in the 6kHz frequency in the DPOAE test, can be justified by the absence of a control group, that is, in this research, both the groups were exposed to noise, in lower or higher levels, that is, both revealed risk factor for hearing loss.…”

“…Nevertheless, in many cases, the hearing alteration is not readily evidenced in the audiometry. Several studies have recognized that even the individuals exposed to occupational noise within the normal hearing threshold, revealed alterations in the register of otoacoustic emissions, both through transient stimuli and the product distortion, evidencing the relevance of such tests for the HLIN precocious diagnosis [9][10][11][12][13] . Frequently associated to buzzing, the hearing loss can also unveil other hearing symptoms, such as hypoacusia, vertigo 14 , recruitment, besides other extra-hearing ailments, such cephalalgia, insomnia, stress, poor concentration, among others 5 .…”

Efeitos do mp3 player na audição

“…Otoacoustic emission distortion products are obtained as the results of vibratory energy generated at the cochlea, which can be measured using a microphone coupled to the ear of the individual tested 31 . Thus, cochlear changes resulting from exposure to high sound pressure levels can cause early changes in the amplitude of otoacoustic emission distortion products, that originate in the organ of Corti, the outer hair cells 32 .…”

Avaliação do dano gerado pelo ruído nas células ciliadas externas de professores do ensino fundamental de uma regional de ensino do Distrito Federal

“…Este excesso de ruído pode perturbar o trabalho, o descanso, o sono, prejudicar a audição e causar ou provocar reações psicológicas, fisiológicas e patológicas (4,(8)(9)(10).…”

“…De acordo com a legislação brasileira (15,16) (8,(18)(19)(20). Desta forma, as EOA podem melhorar a eficácia dos programas de conservação auditiva por fornecer informações mais diretas e confiáveis de alterações precoces e danos à orelha interna (21).…”