Civil Engineering and Architecture 6(2): 71-77, 2018 http://www.hrpub.org DOI: 10.13189/cea.2018.060204 A Modern Standardized Method for Predicting Community Response to Aircraft Noise Sanford Fidell Fidell Associates, Inc., 23139 Erwin Street, Woodland Hills, United States Copyright©2018 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract National (and in some cases, state) legislation in the United States requires prediction of community response to aircraft noise exposure as part of the disclosure of environmental effects of proposed construction of airport infrastructure. Formulation of transportation noise policy and systematic regulation of transportation noise require similar predictions. Historically, such predictions have been based on dosage-response functions derived from univariate correlational analyses in which cumulative noise exposure serves as the sole predictor of annoyance. Such functions typically ignore major differences in annoyance prevalence rates in communities with similar levels of noise exposure, and leave much of the variance in the relationship between exposure and community response unaccounted for. More complex regression models with additional predictor variables can account for more variance, but are ill-suited for regulatory purposes. A recently revised international standard, ISO 1996-1:2016, describes a causal (rather than correlational) prediction method known as Community Tolerance Level (“CTL”) that addresses the limitations of dosage-response functions derived by univariate regression modeling. CTL-based predictions of the prevalence of a consequential degree of aircraft noise-induced annoyance can account for notably more variance in the relationship between noise exposure and annoyance than univariate regression predictions. The CTL approach also provides a consistent rationale for defining the significance of noise exposure, and a systematic approach to regulation of transportation noise. Keywords Transportation Noise, Community Response to Noise, Noise-induced Annoyance, Noise Regulation, CTL 1. Objective This tutorial describes the Community Tolerance Level (abbreviated CTL, and represented symbolically in mathematical expressions as L ct ) approach to estimating the prevalence of transportation noise-induced annoyance in communities. It also distinguishes the approach, and the dosage-response functions that it yields, from earlier, regression-based curve fits. It further shows how CTL analysis permits systematically-derived regulatory policy. 2. Introduction Airports are essential elements of air transportation networks that are frequently described by their proponents as engines of economic development. In economic terms, however, residential exposure to aircraft noise in airport neighborhoods is a “negative externality”: a cost that is not fully reflected in passenger airfares, air freight charges, and airport operating budgets. Opportunity costs, such as restriction of real estate development and other costs associated with aviation-related land use zoning, in combination with losses of property tax revenue to local jurisdictions, are among the unintended consequences of airport operation that are rarely reflected in airport economic impact analyses. At smaller airports, these economic and political costs may be so extensive that they can challenge the assumption that aviation-related land uses are the best and highest for planning purposes. Informed regulation of aircraft noise exposure in the vicinity of airports seeks to balance conflicting societal interests in support for air transportation services on the one hand, against interests in habitable and sustainable residential neighborhoods on the other hand. Such regulation requires an answer to the question “How much noise is too much noise?” A simplistic answer to the question is often expressed in the form of a single, fixed threshold of “significance” of cumulative, long-term aircraft noise exposure. The U.S. Federal Aviation Administration (“FAA”) and other transportation noise regulatory agencies have adopted the position that the prevalence of a consequential degree of aircraft