This standard specifies laboratory-based procedures for measuring, analyzing, and reporting the passive noise-reducing capacity 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 trained-subject fit, is intended to describe the upper
limits of hearing protector performance for devices fitted by carefully trained users. The second
method, designated inexperienced-subject fit, is conducted with persons with little or no experience
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 et al., 1998).