Extended high‐frequency audiometry and noise induced hearing loss in cement workers

• DOI: 10.1002/ajim.20580
• Publication Date: 2008-04-07T15:16:52Z
• Authors: Giuseppina Somma; Antonio Pietroiusti; Andrea Magrini; Luca Coppeta; Carla Ancona; Stefano Gardi; Marco Messina; Antonio Bergamaschi
• Keywords: Adult; Male; noise; age distribution; Time Factors; audiometry; cement industry; Regression Analysi; 333; ear protection; 03 medical and health sciences; Settore MED/44 - MEDICINA DEL LAVORO; 0302 clinical medicine; Audiometry; Risk Factors; Occupational Exposure; Humans; controlled study; adult; age distribution; article; audiometry; cement industry; controlled study; ear protection; hearing loss; human; industrial worker; major clinical study; noise; occupational exposure; Adult; Aged; Audiometry; Construction Materials; Female; Hearing Loss; Humans; Male; Middle Aged; Occupational Exposure; Occupational Health; Regression Analysis; Risk Factors; Time Factors; human; Hearing Loss; Occupational Health; industrial worker; Aged; Construction Materials; adult; Risk Factor; article; occupational exposure; hearing lo; Middle Aged; major clinical study; Construction Material; Regression Analysis; Female

AbstractBackgroundIt has been suggested that extended high‐frequency audiometry (EHFA) might be more sensitive than conventional audiometry in detecting early signs of hearing impairment. However, this technique has not been adequately tested in an occupational environment. We therefore investigated the usefulness of this method in noise‐exposed workers.MethodsWe compared conventional frequency audiometry (0.25–8 kHz) and EHFA (9–18 kHz) in 184 noise‐exposed and 98 non‐noise‐exposed workers.ResultsBoth methods showed significantly higher threshold levels (P < 0.05) in noise‐exposed workers for most of the tested frequencies; however, the differences were more marked for EHFA, especially in young exposed workers. Significant differences in the EHF range were detected also in the subgroup of noise‐exposed workers with normal findings at conventional audiometry. Stepwise regression analysis showed that in 21‐ to 40‐year‐old workers the noise effect was largely predominant at both conventional audiometry and EHFA, whereas in older subjects the noise effect was predominant up to 6 kHz frequency, the effect of age being significantly greater at higher frequencies.ConclusionsThese data indicate that EHFA is more sensitive than conventional audiometry in detecting noise induced hearing loss. However, hearing loss in the EHF range seems an age‐dependent phenomenon with progression into the lower speech range frequencies with increasing age. These changes seem to be accentuated in the early years by noise exposure, suggesting that EHFA could represent a useful preventive measure in young exposed workers. Am. J. Ind. Med. 51:452–462, 2008. © 2008 Wiley‐Liss, Inc.