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If a tree falls in the woods, and no one is around to hear it... it may have been recorded!
Efforts to protect the acoustical environment in our national parks are driven by NPS management policies. But before any action can be taken, park planners and managers need reliable data about a park's existing acoustical environment. What natural and cultural sounds can be heard at the park? What types of human-caused noises can be heard? Where, when, and how often are they heard, and how loud are they?
Through sound monitoring efforts, parks can learn about the acoustical environment as a whole and identify desirable and appropriate sound sources, as well as those that are undesirable in the park setting. Information gathered can then be used to identify the potential impacts of non-natural sounds and proposed developments or actions that may affect the acoustical environment.
Noise modeling software can help to predict how sounds will spread across a park landscape. To learn more about noise modeling, view this presentation by NPS Biologist Katie Nuessly (pdf 2.5MB).
NSNSD summarizes sound measurements taken in national parks in a Natural Resource Report series. Click here to see a list of available reports.
If you're interested in learning how to conduct acoustical monitoring, you can download the Acoustical Monitoring Training Manual (pdf 2MB).
If you work in a park and are interested in technical assistance on a sound-related topic, view this presentation to learn how we can help (pdf 2MB).