Human-related noise is doubling background sound levels in 63% of U.S. protected areas, where manmade disturbances are supposed to be reduced, a new study reveals. The results highlight the magnitude by which human noise pollution, often considered an urban problem, is encroaching into more remote expanses. Noise pollution can have a profound effect on wildlife, for example by reducing the ability of prey to hear predators approaching or interfering with the ability of animals to find a mate. Even plants can be affected by noise pollution if herbivores, or rodents that disperse plant seeds, alter their behavior or location because of the sound disturbance. Such changes can have cascading effects on ecosystems. To quantify the extent of noise pollution across the U.S., particularly in protected areas designed to be safe havens for biodiversity, Rachel Buxton et al. recorded sounds at 492 sites across the country. They used a computer algorithm to establish a baseline, or natural sound level, for the various areas, given each's unique geospatial features. They found that background noise exceeded 3 decibels (dB) in 63% of protected areas, and 10 dB in 21% of protected areas; essentially, a doubling and ten-fold increase in background noise, respectively, in these locations. Wilderness areas were found to have the lowest exposure to noise pollution, yet 12% of these areas still experience anthropogenic sound levels 3 dB above natural levels, the authors report. Protected areas with more stringent regulations had less anthropogenic noise; for example, designated critical habitat within protected areas experienced 56% lower noise exceedance than habitats in unprotected areas. In a related podcast, Buxton goes into detail about how various areas are affected by noise pollution, noting that the data collected by her team points to "low-hanging fruit" for mitigating noise pollution.