Many protected natural areas are chronically exposed to noise. Noise exposure grows faster than the human populations whose activities generate noise. Data accumulate regarding masked hearing performance in animals, which can be coupled with models of sound propagation to predict reductions in the spatial extent of auditory awareness with elevated background sound levels. The emergence of predictive models of noise masking effects recommends a reassessment of field studies of wildlife responses to noise to identify the potential scope of this problem. A review of this literature reveals a substantial and diverse collection of scientific papers whose findings are plausibly related to masking effects and an increasing number of more decisive results from studies that were designed to control for other confounding factors.
Available at: http://works.bepress.com/jesse_barber/7/