Ear Protection Validation System

A new Field-Microphone in Real Ear (F-MIRE) Field Attenuation Estimation System (FAES) is proposed. The insertion loss measurements will utilize a sub-miniature microphone mounted deep in the ear canal. An ultra-thin flat flexible cable (FFC) will connect the microphone to the PC-based analysis module. Human subject and test fixture verification tests have been performed demonstrating that the FFC has no significant effect on insert-type hearing protector attenuation. The FAES system will be compatible with all types of hearing protection, including muffs, inserts, muffs plus inserts, and active noise control devices of either muff- or insert-type. The microphone will be encased in a proprietary, acoustically transparent, removable encasement that will maintain the microphone in a proper measurement position while preventing contact between the microphone and the delicate ear canal walls. The analysis hardware and software will present attenuation data in octave or third-octave band format. A single number Personal Attenuation Rating (PAR) will be generated from these octave band data, and other metrics such as predicted Time-Weighted Average (TWA) exposure, noise dose, and maximum allowable exposure.