The variety of sounds you hear in national parks creates what is called the park's soundscape. These sounds come from a combination of sources, including wildlife communication and behavior, wildlife habitat, cultural-historic features, wilderness character, and ecological processes. They are considered to be essential to the park environment as well as your enjoyment. The goals of the National Park Service are to protect parks' overall sound environments. The NPS wants you to be able to hear this range, from rushing waterfalls to bird songs.
As sound levels increase in parks, so does the need for sound management. Managing sounds and reducing noise improves the condition of other national park resources, like animals, plants, land, water, and historic sites. (See Effects of Noise.) It also improves the quality of your visitor experience, including increased chances of seeing wildlife.
Parks help do their part to reduce the effects of noise by using quieter machines and motors, creating sound barriers to contain loud activities, scheduling noisy events at times of least impact, creating quiet zones, and encouraging park visitors to be mindful of their presence during park outings and activities.