Park Service to work with a manufacturer to design quieter equipment or bring down the price on existing quiet equipment. Shop and field verification can ensure compliance with noise specifications.


After going over the major points, Cooper opened up the session for discussion. Participants wondered whether procurements are limited to American-made products, which would impede the use of EU guidelines, but it was pointed out that many products made for sale in the European Union are also made by American manufacturers. Products assembled in the United States may also be allowable under the Buy America provisions.4 EPA has some rules in effect for purchasing quiet products, and the Park Service could work with the agency to create or enforce purchasing criteria. A complete inventory of NPS equipment would enable the Park Service to set targets and track noise performance over time.

Several options were mentioned for enhancing NPS staff awareness of noise levels. Participants discussed the value of setting up long-term noise monitoring stations in the parks to track progress and pointed out that it would be important to differentiate between disruptive noises and appropriate sounds. Labels on equipment would raise awareness by, for example, reminding users that a chainsaw can sometimes be heard two miles away. In Sequoia and Kings Canyon National Park the management teams took generals from a nearby base into the backcountry so they could hear the impact of their jets.

There was general agreement that having choices and being informed helps visitors to feel that they are in control of their options; an Air Force study done in cooperation with NPS demonstrated that warning people about noise ahead of time raised their tolerance of it. Thus a website could list the location(s) of noisy operations on a daily basis so that visitors can avoid those areas.

Participants also discussed tracking visitor movement and noise exposure. Providing visitors with GPS trackers can be useful, but that strategy would need to be combined with reliable acoustic monitoring. Cell phones with sound-level meter applications are an option, but many attendees expressed concern about their accuracy. Another participant pointed out that letting people report their perceived noise


4 An overview of Buy America is available at

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