Postural body sway and exposure to high-energy impulse noise.

Detailed neurological and audiological examinations and body-sway measurements with a stable platform were carried out on 60 subjects who had been exposed to high-energy intermittent noise from firearms and had various degrees of noise-induced hearing loss. The results were compared with those for 115 healthy controls. The exposed subjects showed significantly more body sway, estimated as movement of the centre of gravity in the horizontal plane, than the controls. This swaying correlated poorly with the recalled level of noise exposure, though subjects with more severe hearing loss (by audiometric deterioration of high-frequency sound, 4 kHz and 6 kHz) showed more sway than those with less severe hearing loss. Age was not significantly correlated with body sway among the controls but men seemed to sway more than women. These results suggest subclinical disturbance of the vestibular system among subjects with impulse-noise-induced hearing loss.