Method for Assessing A-Weighted Auditory Risk Limits for Protected Ears

摘要

Recent noise exposure studies employ A-weighted measures as the basis for estimating varying degrees of potential auditory risk. Since most auditory risk criteria are based on unprotected exposures, aerospace applications require adapting the criteria to attenuated conditions. The report provides specific guidance for evaluating conditions of noise exposure when personal ear protection is worn (headsets or earplugs). Generalized spectra are presented for noise measured within cockpits of 249 aircraft divided into eleven groups, each representing a different airframe-to-powerplant mating. A-weighted levels for attenuated and nonattenuated noise are shown for each of the eleven groups of aircraft included in this study. Relationships between C- and A-weighted values for different spectra (octave bands) are described, and the use of C--A as a correction factor is evaluated. (Author)