TagNoise(196)

Currently, FAA law has extremely complicated rules for establishing a noise boundary around airports. (A noise boundary is a geographic area inside which there is a certain acceptable noise level.) This is referred to as the DNL65. and it has several major flaws. The FAA Reauthorization Act Of 2018 attempted to address these flaws in several ways. This letter, from a caucus of Congressmen engaged on airport community issues complains to the Administrator that the spirit of the law is not being adhered to and demands that he make attempts to put his agency into compliance. The language is fairly technical, however there are a couple of basic points they raise: First, that the noise boundary be determined by actual noise measurements (currently the noise boundaries are 'modeled' and those calculations often do not reflect in any way the lived experience for residents.) Second, that the 'acceptable' noise level of sixty five decibels (hence DNL65) has been determined to be far too high to conform with current understandings of healthy living.

Washington State's Substitute House Bill 1847, signed into law on March 25, 2020, expands the aircraft noise abatement programs available to port districts by lowering the threshold for eligibility from airports serving more than 900 scheduled jet flights per day (previously 20). The law also enlarges the geographic 'impacted areas' around runways where noise relief programs—such as soundproofing, property acquisition, and transaction assistance—can be offered, extending coverage from six to ten miles north and up to thirteen miles south of runway ends, and from one to two miles from runway centerlines.

Washington State's Substitute House Bill 1847, signed into law in March 2020, expands the aircraft noise abatement programs available to port districts by lowering the qualifying threshold from 900 to 20 scheduled jet flights per day and extending the geographic boundaries of 'impacted areas' around airport runways. The law allows port districts to pursue noise relief measures—including property acquisition, soundproofing, transaction assistance, and mortgage insurance—for communities affected by aircraft noise. It amends three existing state statutes (RCW 53.54.010, 53.54.020, and 53.54.030) and took effect on June 11, 2020.

This April 2020 FAA Report to Congress evaluates alternative noise metrics to the current Day-Night Level (DNL) 65 decibel standard used to measure community aircraft noise exposure, as required by the FAA Reauthorization Act of 2018. The report reviews the history and definitions of various noise measurement tools, explains why no single metric can address all aviation noise situations, and examines the roles of both noise modeling and actual noise sampling. It was produced in response to congressional direction to assess whether better methods exist for capturing and addressing community concerns about airplane noise.

A comprehensive review examining the cardiovascular health impacts of traffic noise exposure, with particular emphasis on nighttime noise effects. The study discusses WHO guidelines, mechanistic pathways involving oxidative stress and vascular dysfunction, and epidemiological evidence linking noise exposure to heart disease, stroke, and other cardiometabolic conditions.

This document presents findings from a Sea-Tac Airport Ground Noise Study, shared at the Highline Forum on November 20, 2019. It explains how aircraft ground noise travels and changes with distance, noting that sound levels drop by 6 dB every time the distance doubles and are further reduced by atmospheric absorption and soft ground surfaces. The study also covers how temperature gradients affect noise, with sound bending upward in normal conditions and downward during temperature inversions, potentially increasing noise impacts on nearby communities.