Comparison of percentile and equivalent sound level criteria for construction projects

Abstract

Community ordinances and construction specifications widely use equivalent sound levels, and more often maximum sound pressure levels, to establish limits on environmental noise. In the case of construction, limits on noise expressed as maximum sound levels or equivalent sound levels can be either unreasonably permissive or unreasonably restrictive. It will be argued and shown that expressing construction noise limits as percentile sound levels offers a more realistic assessment of noise impact and can be more useful in understanding construction noise impacts. This presentation will discuss the advantages and disadvantages of limits expressed as equivalent sound levels, maximum sound levels, and percentile sound levels. Methods of analysis and results using each type of descriptor will be discussed. These methods will be compared using actual probability density functions and equivalent sound levels measured for construction operations. The presentation will close with the author’s suggestions for managing construction noise control projects on the basis of his firm’s 20 years of experience conducting construction noise and vibration analyses on a wide variety of construction projects including highway, transit, and building projects.