Origins of Soundscape Monitoring in Denali

Soundscapes, the combined sounds from natural and non-natural sources, are recognized as an important resource in national parks. The natural soundscape is generally comprised of two main sound categories—those from biological or those from physical sources.

Organisms such as birds, frogs, and plants, create biological sounds, while forces such as wind, rock fall, and rivers, create physical sounds. These two types of sounds can be used to characterize different habitats. The specific soundscape characteristics are an important attribute of Denali National Park and Preserve’s (Denali) natural systems, for non-natural sounds can obscure or disturb ecological functions, as well as adversely influence visitor experiences (NPS 1995).

Natural soundscapes are components of “the scenery and the natural and historic objects and the wildlife” as protected by the Organic Act (Public Law 64-235). They were specifically recognized and protected by the National Parks Overflights Act of 1987 (Public Law 100-91). Due to ongoing concern about aircraft overflight noise, the National Parks Air Tour Management Act was established, which requires the Federal Aviation Administration and the National Park Service to cooperatively develop air tour management plans for any park where commercial air tour operations exist or are proposed (Public Law 106-181).

Although Alaska parks were excluded from the act, they were not excluded from aircraft noise and other influences on the natural soundscape and visitor experience.