14 CFR § 161.9
Designation of noise description methods
July 13, 2020
For purposes of this part, the following requirements apply:
(a) The sound level at an airport and surrounding areas, and the exposure of individuals to noise resulting from operations at an airport, must be established in accordance with the specifications and methods prescribed under appendix A of 14 CFR part 150; and
(b) Use of computer models to create noise contours must be in accordance with the criteria prescribed under appendix A of 14 CFR part 150.