The objective of this project was to develop a "toolkit" to assist in the measurement and analysis of sound from heavy-lift helicopters used in helicopter logging operations, escpecially in the Pacific Northwest and as it relates to impacts to the Northern spotted owl and the Marbled murrelet.

The toolkit provides:

• a literature search to identify current research in the field of noise assessment/measurement to quantify noise impacts to wildlife (especially T&E species). Click here to view the Literature Search.

• a noise measurement study of two heavy-lift helicopters (the Boeing Vertol 107 and the Kaman KMAX) taken in the field during helicopter logging operations to determining where the 92dBA contour occurs around the helicopters. (Note: The 92dBA has been identified as the "injury threshold" for the Northern spotted owls and the Marbled murrelets by the US Fish & Wildlife Service's Western Washington Fish & Wildlife Office for Endangered Species Consultations purposes. ) Click here to view the Helicopter Sound Report.

• an evaluation of several sound level meters used in the Pacific Nortwest Region and reports on their ease of use, accuracy, and cost to rent/buy equipment. Click here to view the Sound Meters Evaluation Report.