Development of a new standard laboratory protocol for estimating the field attenuation of hearing protection devices. Part I. Research of Working Group 11, Accredited Standards Committee S12, Noise

This paper describes research conducted by Working Group 11 of Accredited Standards Committee S12, Noise, to develop procedures to estimate the field performance of hearing protection devices (HPDs). Current standardized test methods overestimate the attenuation achieved by workers in everyday use on the job. The goal was to approximate the amount of attenuation that can be achieved by noise‐exposed populations in well‐managed real‐world hearing conservation programs, while maintaining acceptable interlaboratory measurement variability. S12/WG11 designed two new laboratory‐based protocols for measuring real‐ear attenuation at threshold, with explicit procedures for subject selection, training, supervision, and HPD fitting. After pilot‐testing, S12/WG11 conducted a full‐scale study of three types of earplugs and one earmuff tested by four independent laboratories using both protocols. The protocol designated as ‘‘subject‐fit’’ assessed the attenuation achieved by subjects who were experienced in threshold ...