Tour Helicopter Noise Intrusions on the Soundscape at Badlands National Park during April-October 1999
Foch JD. 2000. Tour Helicopter Noise Intrusions on the Soundscape at Badlands National Park during April-October 1999. Foch Associates. Danville, CA
Sound levels in BADL were measured continuously (every second) for six months, at a site between the northern approach to Cedar Pass and the Window Trail, from mid-April to mid-October in 1999. The minimum sound level was 28.5 dBA, and the maximum was 94.3 dBA. Sound levels were less than 27 dBA for only 2.5 hours out of six months, and greater than 60 dBA for only 16 hours.