Abstract:

The at-ear noise exposure of hikers created by sporadic aircraft overflights in an outdoor recreational setting was measured on public lands underlying an active military operations area. Cumulative noise levels for entire hikes and for shorter time intervals were compared with conventional (place-oriented) noise monitoring records. Variability in personal aircraft noise exposure, even of hikers on the same itinerary but at different times of day, was so great as to call into question the adequacy of conventional noise exposure measurement and aircraft noise exposure modeling as representations of the actual aircraft noise experience of outdoor recreationists. Distributions of closest points of approach of aircraft to hikers (derived from radar flight track information and time-stamped geo-coding of hikers' paths) were examined as an explanatory mechanism for the variability. [Work supported by U.S. Air Force Air Combat Command.]