A Comparison of Three Methods for Measuring the Attenuation Provided by Insert-Type Hearing-Protective Devices

To effectively implement an occupational hearing conservation program, employers must know the amount of attenuation (noise reduction) provided by the hearing protective devices used by their employees. Currently standardized test methods, performed under laboratory conditions, cannot be easily implemented in industrial settings, and previously proposed field methods have depended upon the use of special headphones which are not typically available in the workplace. These problems have led many occupational hearing conservationists to use standard audiometric headphones to evaluate the attenuation provided to employees using insert-type hearing-protective devices. There has, however, been little research into the validity of using standard audiometric headphones to determine attenuation values. The purpose of this study was to describe a procedure for determining the attenuation of insert-type hearing-protective devices using standard audiometric earphones, typical industrial audiometric equipment, and other easily obtainable materials