Estimation of sound pressure level exposures from sound power level measurements of powered hand-tools

Abstract

As part of a long-term goal to reduce noise-induced hearing loss in the construction industry, the National Institute for Occupational Safety and Health (NIOSH) estimated the A-weighted sound pressure level at the operator's ear (L pA,est ) from the A-weighted sound power (L WA ) measurements of 118 various model powered hand tools using the diffuse-field point source model Eyring theory. L pA,est from the model are compared to sound pressure measurements (L PA,meas ) acquired from a microphone located in the nominal hearing zone of a simulated powered hand tool operator. This paper provides a basis for the direct substitution of L WA for L pA,meas and a comparison of L pA,est to L PA,meas . The magnitude of L WA is found to be a reasonable predictor of the magnitude of sound pressure level exposure, or L PA,meas , that a powered hand tool operator might experience across a variety of acoustical environments. As such, L WA can be used directly to select appropriate hearing protection and estimate worker' noise exposure. L WA can be measured for all power tools with appropriate loading conditions; however, measuring the sound pressure levels for all combinations of powered hand tools and acoustical environments in the construction industry is not feasible. Purchasers and users of those tools deserve a viable method of estimating noise exposure.