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Urban noise pollution, generated primarily by road traffic, construction, and aviation, has been linked in numerous epidemiological studies to effects extending well beyond simple annoyance. Chronic exposure to elevated noise levels, particularly at night, has been associated with disrupted sleep architecture, elevated stress hormone levels, and over the long term, increased risk of cardiovascular conditions such as hypertension. Unlike air pollution, which can sometimes be filtered indoors, noise readily penetrates standard window glazing, meaning residents near major roads or flight paths experience continuous exposure even inside their homes. Some cities have responded by installing noise barriers along highways or restricting nighttime flights, but researchers note that such measures typically address only the loudest, most localized sources, leaving the cumulative effect of widespread lower-level ambient noise largely unaddressed.