TagSIRRPP(62)

This August 2025 technical report by Harris Miller Miller & Hanson Inc. (HMMH) presents the results of interior sound insulation testing conducted at 28 homes near Seattle-Tacoma International Airport (SEA) in July 2025. Using FAA-approved measurement methods, acoustical engineers tested every habitable room in each home to determine how much aircraft noise penetrates indoors, with a threshold of 45 decibels (dB) required for a home to qualify for sound insulation assistance. Of the 28 structures tested, only two met the 45 dB qualification threshold, while nine others had at least one room exceeding that level but did not qualify under current FAA policy.

Harris Miller Miller & Hanson Inc. (HMMH) conducted sound insulation measurements at 30 homes near Seattle-Tacoma International Airport in June 2025 to determine whether interior noise levels meet the federal threshold for sound insulation assistance. Using FAA-approved testing methods, the study found that only 3 of the 30 homes had median interior Day-Night Average Sound Levels (DNL) at or above the qualifying 45 dB threshold, while an additional 3 homes had individual rooms exceeding that level. The results inform eligibility decisions under the SEA Repair and Replacement Program, which is governed by FAA Advisory Circular 150/5000-9B and the Airport Improvement Program Handbook.