Soundscape Preservation and Noise Management:Grand Canyon National Park (GCNP) is continuing to follow the concepts put forth in Directors Order #47 (sunset date of 2004) as its direction for the park's soundscape program.
GCNP defines the natural soundscape as "the natural ambient sound level of the park." It is comprised of the natural sound conditions in a park which exist in the absence of any human-produced noises. These conditions are actually composed of many natural sounds, near and far, which often are heard as a composite, not individually. In an acoustic environment subjected to high levels of human-caused sound, natural ambient sounds may be masked by other noise sources.
The natural soundscape is an important resource of this park, and there are important relationships between how this environment is perceived and understood by individuals and society.
At GCNP, natural ambient sound is considered synonymous with the term "natural quiet." This definition is used as the basis for determining the "sound environment" for park planning purposes and other environmental compliance actions stemming from human activity that may produce inappropriate or intrusive impacts on the park soundscape.