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

摘要

As part of along-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,L-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. LpA,est from the model are compared to sound pressure measurements (L-pA,L-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 LpA,meas and a comparison of L-pa,L-est to L-pA,L-meas. The magnitude of L-WA is found to be a reasonable predictor of the magnitude of sound pressure level exposure, or LpA,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. (c) 2007 Institute of Noise Control Engineering.