TagHarris Miller Miller & Hanson(3)

This technical memorandum from Harris Miller Miller & Hanson Inc. (HMMH), dated June 5, 2026, presents the results of interior sound insulation testing conducted in April 2026 for 30 homes near Seattle-Tacoma International Airport as part of the SEA Repair and Replacement Program. Acoustical engineers measured how well each room in these homes reduces outside aircraft noise, finding that only 4 of the 30 structures met the FAA's minimum threshold of 45 decibels of interior noise to qualify for sound insulation treatments. An additional 16 homes had at least one room exceeding that threshold, suggesting potential benefit from window and door upgrades, though current FAA policy does not require treatment based on individual room results alone.

This guide, produced by law firm Cutler & Stanfield in conjunction with acoustical consultants Harris Miller Miller & Hanson Inc., explains FAA regulations governing airport noise under the Airport Noise and Capacity Act. It is intended to help airport proprietors, community organizations, and local governments understand the federal rules that control aircraft noise levels and airport operational capacity. The guide draws on the firms' extensive experience advising clients on noise policy and drafting noise rules at major airports across the United States.

The 2018 FAA Reauthorization Act (H.R. 302) includes 14 provisions related to aircraft noise, several of which directly affect airports like Sea-Tac, including requirements for updated noise exposure maps, new community noise concern processes, and health impact studies. Key provisions call on the FAA to study alternative noise metrics to replace the current DNL standard, appoint regional ombudsmen to address noise complaints, and review how NextGen flight path changes have affected surrounding communities. Airports are advised to monitor FAA progress on these studies, as potential changes to the 65 dB DNL threshold and other noise compatibility guidelines could significantly impact community relations and environmental reviews.