The Schultz curve 25 years later: A research perspective

Abstract

The contemporary technical rationale for assessing effects ("impacts") of transportation noise on communities rests in large part on a purely descriptive dosage-effect relationship of the sort first synthesized by Schultz [J. Acoust. Soc. Am. 64, 377-405 (1978)]. Although U.S. federal adoption of an annoyance-based rationale for regulatory policy has made this approach a familiar one, it is only one of several historical perspectives, and not necessarily the most useful for all purposes. Last reviewed by the U.S. Federal Interagency Committee on Noise (FICON) 10 years ago, the accuracy and precision of estimates of the prevalence of a consequential degree of noise-induced annoyance yielded by functions of noise exposure leave much to be desired. This tutorial article traces the development of the dosage-effect relationship on which FICON currently relies, in a wider historical context of efforts to understand and predict community response to transportation noise. It also identifies areas in which advances in genuine understanding might lead to improved means for predicting community response to transportation noise.

Effect of noise dose bin-width on dose-response curves

“…There are many reasons to bin noise data: calculation of %HA, easy understanding of results for policy, 2 and the development of curve-fitting algorithms for noise annoyance relationships before computers were generally used for analysis and binning reduced the amount of data processing needed. We, however, offer an alternative to the binning of noise: no binning.…”

“…While there has been some debate on the shape of the dose-response curve [1][2][3] -a topic not addressed in this paper-it is common practice 4 to use a doseresponse curve to predict the %HA given a noise dose (i.e., the day-night level; DNL). When this method is employed there is typically little to no mention of binning, and it is left to the researcher to make an often subjective choice on how to bin the data.…”

No barrier at the boundaries: implementing regional frameworks for noise management in protected natural areas

“…Director's Order #47 (NPS 2000) requires every park unit to develop a soundscape management plan to ensure the preservation of acoustic resources. These policies clearly declare very protective standards for noise management, in stark contrast to community noise practices based on maximum tolerable noise levels (Fidell 2003). Road projects trigger environmental reviews of noise impacts to adjacent parks and protected natural areas (US Department of Transportation Act 1966 as amended through 1968, section 4(f)).…”

Aircraft noise dose-response relations for national parks

“…That additional analysis was aimed towards (1) understanding the salient aspects or combinations of aspects of the noise exposure (sound level, length of exposure, time between exposures, number of exposure events, and/or source of the noise), (2) identifying additional site-specific or visitor-specific factors which may significantly influence visitor response, (3) developing a homogenous set of dose-response relationships that can be applied beyond the parks/sites represented in those studies, (4) constructing a prediction spreadsheet for use during ATMP development, and (5) providing guidance about future data-taking in types of park environments not yet included. This paper describes that additional analysis and its findings.…”

“…The resulting "Schultz dose-response curve" relates day-night average sound level (DNL, denoted by the symbol L dn ) to the percent of the surveyed residential population that reported high annoyance. Schultz's analysis was later supplemented with additional data, to result in a dose-response curve that still underlies many current federal transportation-noise findings and regulations [4][5][6][7][8][9][10] . This supplemented dose-response relation is widely used as an estimate of community response to transportation noise in residential settings 11 .…”