SAE ARP6973A

This ARP provides two methods for measuring the aircraft noise level reduction of building façades. Airports and their consultants can use either of the methods presented in this ARP to determine the eligibility of structures exposed to aircraft noise to participate in an FAA-funded Airport Noise Mitigation Project, to determine the treatments required to meet project objectives, and to verify that such objectives are satisfied. Standard methods for measuring the noise reduction of façades have been published by the International Organization for Standardization (ISO) and ASTM International, but these methods do not provide the technical details necessary to obtain reproducible results when applied to realistic field situations, particularly when the façades are exposed to aircraft noise sources. This SAE Aerospace Recommended Practice generally follows the methods of previous standards but was developed to provide these additional details. This revision to ARP6973 provides an alternative method for measuring the noise reduction of a building façade using a loudspeaker as the noise source. Experience has shown that there are many situations in the field where it is difficult to position an outdoor loudspeaker according to the guidelines in ARP6973. To overcome this limitation, an alternative methodology has been added that uses an indoor loudspeaker to conduct the measurements. This method provides a measure of the noise reduction that is consistent with measurements conducted using the outdoor loudspeaker method. This revision to ARP6973 also incorporates some improvements to the outdoor loudspeaker method based on experience from field implementation. Most of the changes are minor and relate to wording of various sections to clarify details. More substantive revisions include additional procedures for specific building features, such as porches or balconies, and for measurements in confined spaces.