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What
is a Soundscape?
"Soundscape" refers
to the total ambient acoustic
environment, which is made
up of both natural sounds
and human caused sounds.
Human caused sounds are
not just the sounds that
people themselves produce,
such as talking, but also
the many varied sounds
that attend the presence
of people such as autos,
aircraft, radios, and pets.
People experience soundscapes
by hearing, in the same
way that they view landscapes
by seeing. Soundscapes
may vary in their character
from day to night, from
season to season, and by
changes in numbers of visitors
who also introduce sound
into the environment.
Natural
Ambient Sound Levels
These
are the natural sounds,
and their acoustic properties,
that exist in a park in
the absence of any human-produced
noise. Sounds are emitted
in certain portions of
the sound frequency spectrum.
Sound levels are a combination
of the frequencies produced
by a sound source, and
the amplitude (or sound
pressure level in decibels)
for each frequency. Most
visitors tend to sublimate
the audio portion of the
environment as they experience
its scenic qualities because,
for seeing people, vision
is usually the dominant
sense. However, natural
sound quality is as intrinsic
to the natural setting
as is the view of an undisturbed
landscape.
Acoustic
Ecology
National parks include
a symphony of natural sounds
that is a rich natural
resource important to ecological
communities.
In
the wild, sound is a matter of life and death. Birds,
insects, mammals, and amphibians rely on complex communication
networks to live and reproduce. In habitats where wildlife
vocalizations signify mating calls, danger from predators,
or territorial claims, hearing these sounds is essential
to animal survival.
Research
in bio-acoustics (bio=life, acoustics=sound)
is an important tool for defining the health of natural
habitats. Scientists can discern details about animal
populations and behavior by recording sounds in the
wild. Such bio-acoustical recordings are used in a
variety of ways, including bird censuses, bat echolocation
studies, and marine mammal surveys.
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 How
great are the advantages of solitude!
How sublime is the silence of nature's ever-acting energies!
There is something in the very name of wilderness, which charms the ear
and soothes the spirit of man.
Estwick
Evans, 1818
People
and Sound
The national parks
were established "to conserve
the scenery, the natural
and historic objects and
the wild life therein and
to provide for the enjoyment
of the same in such manner
and by such means as will
leave them unimpaired for
the enjoyment of future
generations..."
If
you live or work near a highway, railway, airport,
or another busy place, you know human-made sounds,
especially noise, too well. The contrasting quiet and
inspiration of park soundscapes is important to you.
Part
of the National Park Service mission is to protect
soundscapes so you can hear sounds as a park's founders
intended. Both the sounds of the wild and the sounds
meaningful in historic settings are protected in the
National Park System. In sites where music, language,
and history help people understand our national heritage,
park soundscapes may include jazz music, battlefield
sounds, or the songs of indigenous people. |
