14 CFR § 150.9 - Designation of noise systems.

---
identifier: "/us/cfr/t14/s150.9"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 150.9 - Designation of noise systems."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "150.9"
section_name: "Designation of noise systems."
chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "I"
subchapter_name: "AIRPORTS"
part_number: "150"
part_name: "AIRPORT NOISE COMPATIBILITY PLANNING"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 106(g), 40113, 44715, 47101, 47501-47504."
regulatory_source: "Docket 18691, 49 FR 49269, Dec. 18, 1984, unless otherwise noted."
cfr_part: "150"
---


# 150.9 Designation of noise systems.

For purposes of this part, the following designations apply:

(a) The noise at an airport and surrounding areas covered by a noise exposure map must be measured in A-weighted sound pressure level (L<sub>A</sub>) in units of decibels (dBA) in accordance with the specifications and methods prescribed under appendix A of this part.

(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.

(c) Uses of computer models to create noise contours must be in accordance with the criteria prescribed under appendix A of this part.