Noise is rarely considered a pervasive problem in society, despite well-documented evidence of its detrimental impacts on both human and wildlife health. And yet, it persists—ubiquitous, irritating, widely accepted, and profoundly impactful. A growing body of research has shown that anthropogenic noise, particularly at high intensities or persistent levels, can significantly affect living organisms, contributing to human health disorders such as cardiovascular disease, and disrupting sensitive wildlife behavior, even in designated protected areas such as national parks.
Anthropogenic noise sources are diverse. They include urban traffic, industrial machinery, tourism and recreation in parks, aircraft overflights, agricultural operations, and military sonar activity in marine environments (Barber et al., 2010; Slabbekoorn et al., 2010). These sounds can travel far from their source, penetrating deep into areas that would otherwise be considered natural or pristine. In fact, noise pollution has been documented in nearly two-thirds of U.S. protected areas, with some locations experiencing sound levels that exceed biological thresholds known to cause harm (Buxton et al., 2017).
In human populations, the effects of chronic noise exposure are well established. Prolonged exposure to environmental noise is associated with cognitive impairment in children, sleep disturbance, increased stress hormone levels, and elevated risk of cardiovascular disease (Basner et al., 2014). For example, a study conducted near major airports found that a 10-decibel increase in aircraft noise was linked to a significant rise in the use of anxiety medication (Hardoy et al., 2005). Similarly, residents exposed to high levels of road traffic noise were 25% more likely to experience depressive symptoms than those in quieter neighborhoods (Orban et al., 2016). Moreover, a large-scale European cohort study reported a strong association between long-term exposure to environmental noise and increased risk of atrial fibrillation and other cardiac conditions (Sørensen et al., 2014).
The impacts of noise pollution extend far beyond human health. Wildlife, which often depends on sound for communication, mating, navigation, and predator avoidance, is particularly vulnerable. Disruption caused by human-generated noise can lead to altered movement patterns, reduced reproductive success, and increased mortality in numerous species (Shannon et al., 2016). For instance, birds have been observed to change the pitch or timing of their songs in response to urban noise, which can interfere with mate attraction and territory defense (Slabbekoorn & Peet, 2003). In marine environments, military sonar has been linked to mass strandings of beaked whales, whose hearing is acutely sensitive and essential for navigation and foraging (Tyack et al., 2011).
Given these pervasive effects, protected natural areas—such as national parks and wildlife refuges—should serve not only as havens for biodiversity but also as acoustic sanctuaries. However, research indicates that even these spaces are increasingly compromised by external noise intrusion. Buxton et al. (2017) found that noise pollution in U.S. national parks can double the background sound levels in some areas, diminishing the experience for visitors and interfering with ecosystem processes.
Anthropogenic noise sources are diverse. They include urban traffic, industrial machinery, tourism and recreation in parks, aircraft overflights, agricultural operations, and military sonar activity in marine environments (Barber et al., 2010; Slabbekoorn et al., 2010). These sounds can travel far from their source, penetrating deep into areas that would otherwise be considered natural or pristine. In fact, noise pollution has been documented in nearly two-thirds of U.S. protected areas, with some locations experiencing sound levels that exceed biological thresholds known to cause harm (Buxton et al., 2017).
In human populations, the effects of chronic noise exposure are well established. Prolonged exposure to environmental noise is associated with cognitive impairment in children, sleep disturbance, increased stress hormone levels, and elevated risk of cardiovascular disease (Basner et al., 2014). For example, a study conducted near major airports found that a 10-decibel increase in aircraft noise was linked to a significant rise in the use of anxiety medication (Hardoy et al., 2005). Similarly, residents exposed to high levels of road traffic noise were 25% more likely to experience depressive symptoms than those in quieter neighborhoods (Orban et al., 2016). Moreover, a large-scale European cohort study reported a strong association between long-term exposure to environmental noise and increased risk of atrial fibrillation and other cardiac conditions (Sørensen et al., 2014).
The impacts of noise pollution extend far beyond human health. Wildlife, which often depends on sound for communication, mating, navigation, and predator avoidance, is particularly vulnerable. Disruption caused by human-generated noise can lead to altered movement patterns, reduced reproductive success, and increased mortality in numerous species (Shannon et al., 2016). For instance, birds have been observed to change the pitch or timing of their songs in response to urban noise, which can interfere with mate attraction and territory defense (Slabbekoorn & Peet, 2003). In marine environments, military sonar has been linked to mass strandings of beaked whales, whose hearing is acutely sensitive and essential for navigation and foraging (Tyack et al., 2011).
Given these pervasive effects, protected natural areas—such as national parks and wildlife refuges—should serve not only as havens for biodiversity but also as acoustic sanctuaries. However, research indicates that even these spaces are increasingly compromised by external noise intrusion. Buxton et al. (2017) found that noise pollution in U.S. national parks can double the background sound levels in some areas, diminishing the experience for visitors and interfering with ecosystem processes.
Photo credit: William Helenbrook
Specific to animals, noise can distract and inhibit communication, impact their use of habitat and even reduce their reproductive potential. Noise pollution can also impact the distribution and behavior of key species that can alter ecosystem integrity. For example, "a bird whose song would normally travel 100 meters would, with a 10-fold increase in noise, have its melody stifled to a 10-meter radius." This problem affects many biological groups such as birds, amphibians , reptiles, fish, mammals, and invertebrates. It also impacts all types of ecosystems including terrestrial, aquatic and coastal.
A study of noise impacts in protected areas in the US found that 12.1% of wilderness areas "still experienced anthropogenic sound levels 3 dB above predicted natural levels, indicating that they are not entirely 'untrammeled by man' as defined by the Wilderness Act (U.S. C. 1131-1136, sec. 3c, 1964)." Wilderness areas are supposed to be remote sites with low background noise. And yet, even our most protected and isolated - last frontiers - are being inundated with noise pollution. This same study found that noise pollution from humans has "doubled sound levels in more than half of all protected areas in the United States—from local nature reserves to national parks—and it has made some places 10 times louder."
Noise was even a problem in 58% of endangered species habitat - in critically protected protected areas - where wildlife experienced 3 to 10 dB of human-induced sound. And studies have found that anthropogenic noise is present in most protected areas and is pervasive in those near developed areas where noise exceeds levels known to impact human and wildlife health. There is some hope in the US because 63% of endangered species experiencing noise pollution in excess of 10 dB had critical habitat partially within federal protected areas.
On the National Park Mission Statement they describe their mission: "The National Park Service preserves unimpaired the natural and cultural resources and values of the National Park System for the enjoyment, education, and inspiration of this and future generations." In other words, the park service is there to provide for the people but also to protect natural wonders. That presently is not happening. Noise doesn't just annoy people, but can counter all the benefits that people experience when they go to some of our natural wonders. Whether it be Green Exercise or Forest Bathing, there is widespread evidence that our green spaces provide innumerable benefits to mental and physical health, but only as long as they are indeed protected from noise.
A study of noise impacts in protected areas in the US found that 12.1% of wilderness areas "still experienced anthropogenic sound levels 3 dB above predicted natural levels, indicating that they are not entirely 'untrammeled by man' as defined by the Wilderness Act (U.S. C. 1131-1136, sec. 3c, 1964)." Wilderness areas are supposed to be remote sites with low background noise. And yet, even our most protected and isolated - last frontiers - are being inundated with noise pollution. This same study found that noise pollution from humans has "doubled sound levels in more than half of all protected areas in the United States—from local nature reserves to national parks—and it has made some places 10 times louder."
Noise was even a problem in 58% of endangered species habitat - in critically protected protected areas - where wildlife experienced 3 to 10 dB of human-induced sound. And studies have found that anthropogenic noise is present in most protected areas and is pervasive in those near developed areas where noise exceeds levels known to impact human and wildlife health. There is some hope in the US because 63% of endangered species experiencing noise pollution in excess of 10 dB had critical habitat partially within federal protected areas.
On the National Park Mission Statement they describe their mission: "The National Park Service preserves unimpaired the natural and cultural resources and values of the National Park System for the enjoyment, education, and inspiration of this and future generations." In other words, the park service is there to provide for the people but also to protect natural wonders. That presently is not happening. Noise doesn't just annoy people, but can counter all the benefits that people experience when they go to some of our natural wonders. Whether it be Green Exercise or Forest Bathing, there is widespread evidence that our green spaces provide innumerable benefits to mental and physical health, but only as long as they are indeed protected from noise.
Noise exceedance of 1.25, 3.01, 6.02, and 10 dB corresponds, respectively, to 25, 50, 75, and 90% reductions in listening area (the area at which an acoustic signal can be detected) for humans. Gray areas are outside the protected area network. Buxton, R. T., McKenna, M. F., Mennitt, D., Fristrup, K., Crooks, K., Angeloni, L., & Wittemyer, G. (2017). Noise pollution is pervasive in US protected areas. Science, 356(6337), 531-533.
As one of our nations most widely supported programs and a program that generates jobs and massive return on investment, it does beg the question: 'why don't we expand them, fund them, and maintain them not only for people but for the wildlife that they are supposed to protect?' Currently 12% of the US is designated protected areas; however, this includes massive areas run by Bureau of Land Management and Forestry Department whose rights are sold out for grazing, mining, logging, oil and gas drilling and growing crops. And to start, in order to mitigate our noise impacts on nature, maybe we should take Edward Abbey's advice from decades ago, "No more cars in national parks," or at least minimize the noise generated by traffic in supposedly protected areas.
Moreover, prioritizing quiet in protected areas aligns with the National Park Service’s mission to preserve both natural and cultural resources “unimpaired for the enjoyment of future generations” (NPS Organic Act, 1916). Noise undermines this mission by degrading ecological conditions and diminishing the sense of solitude, peace, and connection to nature that many visitors seek.
Expanding true protected areas—those that are free from industrial use and managed explicitly for conservation—must go hand in hand with strategies to actively mitigate noise. That means not only protecting more land but ensuring that the character of those places—acoustic, ecological, and aesthetic—is preserved. If we’re serious about conservation, we can’t ignore the soundscapes of wild places. Silence, or at least the natural rhythm of quiet, is more than just an absence of noise; it is a crucial ecological resource.
Moreover, prioritizing quiet in protected areas aligns with the National Park Service’s mission to preserve both natural and cultural resources “unimpaired for the enjoyment of future generations” (NPS Organic Act, 1916). Noise undermines this mission by degrading ecological conditions and diminishing the sense of solitude, peace, and connection to nature that many visitors seek.
Expanding true protected areas—those that are free from industrial use and managed explicitly for conservation—must go hand in hand with strategies to actively mitigate noise. That means not only protecting more land but ensuring that the character of those places—acoustic, ecological, and aesthetic—is preserved. If we’re serious about conservation, we can’t ignore the soundscapes of wild places. Silence, or at least the natural rhythm of quiet, is more than just an absence of noise; it is a crucial ecological resource.
Resources
Evidence of the impact of noise pollution on biodiversity: a systematic map
Is Noise Pollution the Next Big Public-Health Crisis?
Noise pollution is pervasive in U.S. protected areas
Noise pollution is invading even the most protected natural areas
A Modest Proposal: We Need More National Parks
Landmark Investment in Our National Parks Is Underway
Noise pollution is a major problem, both for human health and the environment
Airport noise and wildlife conservation: What are we missing?
Literature Cited
Barber, J. R., Crooks, K. R., & Fristrup, K. M. (2010). The costs of chronic noise exposure for terrestrial organisms. Trends in Ecology & Evolution, 25(3), 180–189. https://doi.org/10.1016/j.tree.2009.08.002
Buxton, R. T., McKenna, M. F., Mennitt, D. J., et al. (2017). Noise pollution is pervasive in U.S. protected areas. Science, 356(6337), 531–533. https://doi.org/10.1126/science.aah4783
Mennitt, D. J., Fristrup, K. M., & Sherrill, K. (2014). A geospatial model of ambient sound pressure levels in the contiguous United States. The Journal of the Acoustical Society of America, 135(5), 2746–2764. https://doi.org/10.1121/1.4869620
Radeloff, V. C., Helmers, D. P., Kramer, H. A., et al. (2019). Rapid growth of the US wildland-urban interface raises wildfire risk. Proceedings of the National Academy of Sciences, 115(13), 3314–3319. https://doi.org/10.1073/pnas.1718850115
U.S. Geological Survey Gap Analysis Project (USGS GAP). (2024). Protected Areas Database of the United States (PAD-US) v3.0. https://www.usgs.gov/core-science-systems/science-analytics-and-synthesis/gap/science/protected-areas
Barber, J. R., Crooks, K. R., & Fristrup, K. M. (2010). The costs of chronic noise exposure for terrestrial organisms. Trends in Ecology & Evolution, 25(3), 180–189. https://doi.org/10.1016/j.tree.2009.08.002
Buxton, R. T., McKenna, M. F., Mennitt, D. J., et al. (2017). Noise pollution is pervasive in U.S. protected areas. Science, 356(6337), 531–533. https://doi.org/10.1126/science.aah4783
Mennitt, D. J., Fristrup, K. M., & Sherrill, K. (2014). A geospatial model of ambient sound pressure levels in the contiguous United States. The Journal of the Acoustical Society of America, 135(5), 2746–2764. https://doi.org/10.1121/1.4869620
Radeloff, V. C., Helmers, D. P., Kramer, H. A., et al. (2019). Rapid growth of the US wildland-urban interface raises wildfire risk. Proceedings of the National Academy of Sciences, 115(13), 3314–3319. https://doi.org/10.1073/pnas.1718850115
U.S. Geological Survey Gap Analysis Project (USGS GAP). (2024). Protected Areas Database of the United States (PAD-US) v3.0. https://www.usgs.gov/core-science-systems/science-analytics-and-synthesis/gap/science/protected-areas