{"data":{"id":"us/14-cfr-150.9","jurisdiction":"us","citation":"14 CFR 150.9","heading":"Designation of noise systems.","body":"For purposes of this part, the following designations apply:\n(a) The noise at an airport and surrounding areas covered by a noise exposure map must be measured in A-weighted sound pressure level (LA) in units of decibels (dBA) in accordance with the specifications and methods prescribed under appendix A of this part.\n(b) The exposure of individuals to noise resulting from the operation of an airport must be established in terms of yearly day-night average sound level (YDNL) calculated in accordance with the specifications and methods prescribed under appendix A of this part.\n(c) Uses of computer models to create noise contours must be in accordance with the criteria prescribed under appendix A of this part.","path":["Title 14—Aeronautics and Space","CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER I—AIRPORTS","PART 150—AIRPORT NOISE COMPATIBILITY PLANNING","Subpart A—General Provisions"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-14.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:20Z","sha256":"e8533434dff1d850529d29ceced31628f4d5c2b039f7284d895db06fc3a3df90","source_id":"us-cfr","stale":true,"prev":"us/14-cfr-150.7","next":"us/14-cfr-150.11"},"notice":"GroundRules: Original legal text. Not legal advice."}