The FAA is seeking comment on a number of noise research projects that the agency has undertaken and has released results of one such study, the Neighborhood Environmental Survey, which found an increased level of annoyance from aircraft noise. These projects could be used to help shape future noise policy, such as a revised use of the Day-Night Average Sound Level (DNL), but the agency said it would not make any determinations until it has considered public and stakeholder input and completed any additional necessary research.
This research comes as the FAA has recognized that aircraft noise is a chief concern for stakeholders. “With the vision of removing environmental constraints on aviation growth by achieving quieter, cleaner, and more efficient air transportation, the FAA has worked closely with a number of industry, academic, and governmental stakeholders to assemble a comprehensive portfolio of research activities (including leveraging research undertaken by others) aimed at guiding investments in scientific studies, analytical tools, and innovative technologies to better understand and manage aircraft noise,” the agency said.
However, the FAA stressed that aircraft noise is complex and so no single set of findings or perspectives can fully guide decisions. Broadly speaking the research is exploring three main themes: effects on individuals and communities; noise modeling, metrics, and environmental data; and, reduction, abatement, and mitigations.
Research on the effects on individuals and communities includes efforts to explore sleep disturbance, interference in children learning, and impacts to cardiovascular, among other areas. The multi-year Neighborhood Environmental Survey (NES), which came in response to a congressional directive, also falls in this category.
That study accumulated survey responses from more than 10,000 people living near 20 “statistically representative” airports across the country. In contrast to earlier surveys, the NES results “show a substantially higher percentage of people highly annoyed over the entire range of aircraft noise levels (i.e., from DNL 50 to 75 dB),” the agency said. “This includes an increase in annoyance at lower noise levels.”
However, the agency added more work needs to be done to assess reasons for this, particularly in factors that can include changes where people choose to live, how they work and live, social media influences, and other societal responses. In addition, the FAA has noted that recent research has shown “that aircraft noise often results in higher levels of annoyance compared to the same level of noise from ground transportation sources.”
The findings come as the FAA notes that the number of people exposed to significant levels of aircraft noise in the U.S. has continuously declined since the mid-1970s, from roughly seven million to just more than 400,000 today. But at the same time, commercial enplanements have grown from 200 million in 1975 to 930 million in 2018.
The agency credited quieter aircraft to the reduction in noise footprints around aircraft, a phase-out of noisier aircraft, noise compatibility and mitigation plans, and collaboration.