Elliott H. Berger
Cabot Safety Corp., 7911 Zionsville Rd., Indianapolis, IN 46268-1657
In 1987, ANSI S12/WG11 (previously designated S12-26) was given an expanded scope and a new title, namely, Field Effectiveness and Physical Characteristics of Hearing Protectors. The WG was directed to explore the problems inherent in using optimum-performance laboratory-derived real-ear attenuation data to estimate achievable and/or typical workplace protection, and to identify or develop procedures that could yield improved estimates of field performance. After careful deliberation, the WG determined that a new laboratory-based real-ear attenuation at threshold procedure with explicitly defined subject selection, training supervision, and fitting techniques could potentially provide useful estimates of obtainable field performance. The WG devised a draft protocol and subjected it to a pilot study [Berger et al., J. Acoust. Soc. Am. Suppl. 1 88, S10 (1990)]. Subsequently, the protocol was modified and utilized in a full-scale test of three types of earplugs and one earmuff, by four independent laboratories. The testing was conducted from September 1990 through December 1991. This presentation begins with an overview of the hearing protection rating problem and the rationale for the activities of WG11, as well as an introduction to the remaining invited papers in the session, which focus on the needs for improved hearing protector attenuation data and the results of the interlaboratory study.