Yellowstone's soundscape is the aggregate of all the sounds within the park, including those inaudible to the human ear. Some sounds are critical for animals to locate a mate or food, or avoid predators. Other sounds, such as those produced by weather, water, and geothermal activity, may be a consequence rather than a driver of ecological processes. Human-caused sounds can mask the natural soundscape. The National Park Service goal is to protect or restore natural soundscapes where possible and minimize human-caused sounds while recognizing that they are generally more appropriate in and near developed areas. The quality of Yellowstone's natural soundscape therefore depends on where and how often non-natural sounds are present as well as their levels.
Acoustic data have been collected since 2003 as part of Yellowstone's Soundscape Program. Automated systems collected digital recordings and sound levels 24 hours a day throughout the year. Targeted measurements collect acoustic data about oversnow vehicles, motorcycles, motorboats, and other noise sources of interest. The natural soundscape is quantified through analyses of the automated system data. Detailed methods and results are posted annually in the winter use reports.