Ready to Rumble: Recreationists Rate Acceptability of Noise in Natural Areas

Recreationists head to the outdoors to experience natural beauty, find a sense of calm, enjoy an adventure or just to get a few hours of peace and quiet. But public lands are managed for more than peace and quiet. Managers have the thorny task of overseeing natural areas for everything from bird watching to all-terrain vehicles and fracking – and some activities are noisier than others.

Understanding how a visitor experiences sound is an important part of a park manager’s job. From the muted chirrup of the American Goldfinch to the rumble of natural gas compressors, a soundscape has a meaningful impact on a visitor’s overall experience. In new research published in Science Direct and led by Zachary Miller at Utah State University’s Institute of Outdoor Recreation and Tourism, he evaluated what levels of human-caused sound were acceptable to visitors … and found some interesting dichotomies.

Using data collected from over 400 onsite visitors to Pennsylvania state forests, Miller and colleagues developed a model to show how a visitor’s experience changes with different levels of sound from natural gas compressors used for fracking, common in the area. Researchers met people onsite and played through headphones different levels of ambient sound collected from compressors. 

Unsurprisingly, the model showed that increased levels of sound from compressors have a negative impact on visitor experiences. The louder the rumble, the more likely visitors were to rate the experience as “unacceptable” in a protected natural area. But when broken down by visitors type, it became apparent that certain types of visitors were a lot more tolerant of human-caused noise than others. Visitors pursuing non-motorized activities such as hiking, biking, fishing and kayaking all rated natural gas compressor sounds as unacceptable at about 55 dBA (about the level of a refrigerator running in your home, or light traffic). 

Motorized users such as ATV riders who reported coming to the area to “experience
a sense of adventure or challenge” were much more tolerant of natural gas compressor sounds, reporting that the noise crossed over the level of acceptability at an extremely high decibel level – 123.87 dBA (about the same level as a balloon popping in close proximity).

The results from this study can be used to help managers of forests plan for high-quality recreational experiences in an era of expanding natural gas extraction. Managers should be mindful that recreation users with motivations for higher adventure or challenge may hold different perceptions about sounds. For instance, sounds that are generally considered to detract from the visitor experience, such as motor sounds and vehicle sounds, may actually add to the visitor experience for some recreation groups like motorized users. Although the reason for this is currently unknown, it may be that these anthropogenic sounds help increase visitor perceptions of safety and awareness.