Statistical assessment behind a standard on hearing protector field attenuation measurement devices.
J Acoust Soc Am 2011 Apr; 129(4)(Part 2):2650
New measurement systems for assessing individual hearing protection device (HPD) performance in the field have been developed over the past several years to address the question of what amount of protection is a given individual getting from an HPD. Although these systems, referred to as field attenuation measurement systems (FAMSs), have the same purpose and produce attenuation values that are presented in similar ways, the underlying technology used to produce a personal attenuation rating (PAR) can be drastically different, ranging from psychophysical tests to objective microphone measurements and involving single or multiple frequency measurements. In an effort to ensure that FAMS provide an attenuation rating that is a both a scientifically valid number and a meaningful reading for the end-user, the members of the American National Standard Institute Working Group 11 have recently been starting to work on a proposed standard to specify the minimum performance criteria for a FAMS to assure it provides data with defined accuracy and precision. The current paper describes the underlying statistical assessments that are considered in the standard. Specifically, the computational details of the number of subjects required for various assessments made within the standard for the determination of the maximum permissible background noise, measurement uncertainty, and HPD fit uncertainty will be presented. The paper will also detail the calculation of the repeatability and reproducibility.
Ear-protection; Ear-protectors; Noise; Noise-control; Noise-levels; Noise-induced-hearing-loss; Injury-prevention; Hearing; Hearing-conservation; Hearing-protection; Auditory-system; Personal-protective-equipment; Work-environment; Work-practices; Noise-measurement; Noise-protection; Noise-frequencies; Standards; Quality-standards; Performance-capability; Equipment-reliability; Permissible-concentration-limits; Exposure-assessment; Exposure-limits
Jérémie Voix, École de Technologie Superieure, Montréal, PQ H3C 1K3, Canada
Journal of the Acoustical Society of America