This standard specifies laboratory-based procedures
for measuring, analyzing, and reporting the
noise-reducing capabilities of hearing protection devices.
The methods consist of psychophysical tests
conducted on human subjects to determine real-ear
attenuation at threshold.
Two methods are provided, differing in their subject
selection, training, hearing protector fitting procedures, and experimenter involvement, but corresponding in all electroacoustic and psychophysical aspects. One method, designated experimentersupervised fit is intended to describe the upper limits of hearing protector performance. The second method, designated subject fit, is conducted with persons naive with respect to the use of hearing protection. It approximates the attenuation that has been achieved by groups of users as reported in real-world occupational studies (Berger and Franks,1996).