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. © 2007 Institute of Noise Control Engineering.

Insertion Loss of Noise Barriers on an Aboveground, Full-Scale Model Longwall Coal Mining Shearer

“…(2) Since the barrier treatments affect primarily direct path noise, the sound pressure levels would have to be deconstructed to determine the direct path component, apply the measured insertion loss, then reconstructed with the measured underground total room absorption coefficients. Hayden and Zechmann (14) estimated sound pressure levels in varied environments for hand tools. Since hand tools are generally operated at arm's length or less (<1 m), sound pressure levels are relatively close to sound power levels.…”