TECHNOLOGY ADVANCEMENTS IN HEARING PROTECTION CIRCA-1995 - ACTIVE NOISE-REDUCTION, FREQUENCY AMPLITUDE-SENSITIVITY, AND UNIFORM ATTENUATION/

Conventional hearing protection devices represent a mature technology that has been widely used since the late 1950s. When worn consistently and correctly such devices can provide suitable hearing protection in many, if not most noise-hazardous or aurally annoying situations. How ever, such devices have often been implicated in compromised auditory perception, degraded signal detection, and reduced speech communicatio n abilities. in some instances this can create hazards for the wearer, or at the very least, resistance to use by those in need of hearing p rotection. Recent technological developments have been used to augment hearing protectors in an attempt to alleviate these problems for the user while providing adequate attenuation. Operational characteristics , design alternatives, performance data, and applications for active n oise reduction, active sound transmission, frequency selectivity, adju stable attenuation, amplitude sensitivity, and uniform attenuation fea tures in hearing protectors are discussed, and recommendations are pro vided.