Comparison of potential dayight average sound level (DNL) replacement metrics

摘要

This paper, using an airport noise context, examines supplemental or alternative noise metrics that could support or replace DNL. The purpose of supplemental or alternative metrics is to help to improve the characterization of community annoyance. Using airport noise exposure as the test case, this paper identifies noise metrics that are not likely to support such improvements, extant information useful for calculating any or all such metrics, and new information useful for calculating such metrics. It was found that DNL values for noise exposure created by aircraft operations correlate very highly with values of most other conventional noise metrics over most geographic and operational settings for a typical airport. This means that little or no improvement in prediction of the prevalence of aircraft noise-induced annoyance may be expected from substitution of another noise metric for DNL. Linear measures of the duration and numbers of noise events in excess of a threshold do not correlate as highly with DNL or other noise metrics in common use. Some special circumstances in which correlations between DNL and other aircraft noise metrics may be poorer include in areas behind departure ends of runways subject to start-of-takeoff-roll noise, and in runway sideline locations exposed to high levels of low-frequency noise created by thrust reverser application.