Acoustical model and theory for predicting effects of environmental noise on people.

The Schultz [(1978). J. Acoust. Soc. Am. 64, 377-405]; Fidell et al. [(1991). J. Acoust. Soc. Am. 89, 221-233] and Finegold et al. [(1994). Noise Control Eng. 42, 25-30] curves present misleading research information regarding DENL/DENL levels of environmental noises from transportation vehicles and the impact of annoyance and associated adverse effects on people living in residential areas. The reasons are shown to be jointly due to (a) interpretations of early research data, (b) plotting of annoyance data for noise exposure from different types of transportation vehicles on a single set of coordinates, and (c) the assumption that the effective, as heard, levels of noise from different sources are proportional to day, night level (DNL)/day, evening night level (DENL) levels measured at a common-point outdoors. The subtraction of on-site attenuations from the measured outdoor levels of environmental noises used in the calculation of DNL/DENL provides new metrics, labeled EDNL/EDENL, for the calculation of the effective exposure levels of noises perceived as equaling annoying. Predictions of judged annoyance in residential areas from the noises of transportation vehicles are made with predicted errors of <1 dB EDNL/EDENL, compared to errors ranging from approximately 6 to approximately 14 dB by DNL/DENL. A joint neurological, physiological, and psychological theory, and an effective acoustical model for the prediction of public annoyance and related effects from exposures to environment noises are presented.