Performance of sound restoration hearing protection in impulsive noise

Hearing protection devices (HPDs) are the principal means of protecting the hearing of a person against harmful levels of noise in highly impulsive noise environments. New HPDs which utilize sound restoration circuitry were measured using a mannequin to assess the performance of these protectors in response to small-arms weapons fire. The results for the peak reduction and attenuation were analyzed for both indoor and outdoor measurements. The performance of the protectors exhibited little dependence with level for impulses between 150 and 170 decibels. The passive performance for a single protector characterized the active performance for these high-intensity impulses. The results were also evaluated using the US Army AHAAH cochlear model. As the peak sound-pressure level underneath the different models of protectors increased, the estimated risk of hearing loss increased. [Work supported by EPA Interagency Agreement DW75921973-01-0.]