The specific problems of noise in military life.

In military life, noise has unusual characteristics and constitutes a serious hazard for hearing. Hearing impairments due to the exposure to weapon noises represent an important prejudice for the health of many soldiers. A special attention is given to (i) the "critical level", (ii) the frequency localization of the threshold shifts, (iii) the actual influence of the protective reflexes of the ear, (iv) the existence of delayed threshold shifts following impulse noise exposures, and (v) the interest of the medical treatment of the acoustic trauma. Damage risk criteria for weapon noises are compared: criteria using the (A-weighted) isoenergy principle represent the best present solution (LAeq = 85 dB). Specific problems related to the use of hearing protection are also discussed.