[Acute unilateral total deafness and vestibular findings after gunshot noise]

Acute acoustic trauma is usually acquired during military service after exposure to impulse or blast wave noise. The typical audiometric shape is a notch centered at about 4 kHz with some recovery above this frequency. This is the first case of an immediate induced unilateral total hearing loss in a young soldier following exposure to gunfire noise.

A 25-year-old right-handed army officer during military training, after realizing a series of five shots with a rifle (G3), immediately experienced on the right ear otalgia, tinnitus and severe hearing loss, without imbalance or dizziness. The pure tone audiogram revealed a cophosis on the right ear without any residual remnants. In order to estimate the extent of the labyrinth damage, a caloric test and vestibular evoked myogenic potentials (VEMPs) were performed, which were both abnormal.

The possible mechanical and metabolic damage effects on the cochlea from the intense gunfire noise were discussed. As the caloric test showed directional preponderance and the VEMPs were totally abolished, it has been concluded that the saccule and to a lesser degree the posterior labyrinth have been also found affected. The importance of wearing hearing protectors such as ear plugs and ear muffs during exposure to intense noise was underlined.