scope:

This standard specifies laboratory-based subjective-method for measuring, analyzing, and reporting the passive noise-reducing capacity of hearing protection devices. The methods consist of psychophysical tests conducted on groups of 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 groups of 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).