Sound Justice: Citizen Science, Noise, and the Quest for Equity

At the start of World War I, thousands of soldiers were coming down with a baffling condition: they became blind, deaf, lost their memory, or developed uncontrollable shaking despite no obvious physical injury. Even stranger, this malady could be triggered by memories of the war even after the fighting had ended. At the time, doctors called what they were seeing “shell-shock,” though today we would call it by a different name: post-traumatic stress disorder. Anything that brought back memories of the trenches could precipitate this condition, but one of the most common triggers was loud noise. An engine backfiring, a firecracker on Independence Day or, in at least one case, simply speaking the word “bomb,” could cause afflicted soldiers to become catatonic or act out memories from the war. All this, the result of a sound. Clearly, sound can have a dramatic effect on our bodies and our minds. But it doesn’t have to be linked to memories of trauma to affect us. Indeed, studies have shown that even exposure to seemingly innocuous sound can impact our health. Low volume, low-frequency traffic noise, for instance, is linked to all sorts of health consequences including poor sleep quality, difficulty concentrating, and even cardiovascular problems. As a result, we now recognize negative sounds as a specific class of pollutant: noise. Noise pollution is the propagation of unwanted sounds in an area. And even though noise doesn’t leave a chemical trace like gas from a smokestack or sludge from a pipe, it affects our health in a similar way. For this reason, the US National Parks Service (NPS) decided to study noise pollution to determine how it is distributed across the country. Much like the Environmental Protection Agency (EPA) uses air and water quality monitors to measure conventional classes of pollution, the NPS’s Natural Sounds and Night Skies Division deploys sensors to record levels of noise. In 2013, they mapped the results of this work across the entire continental US, showing areas of highest and lowest noise pollution.