Quieting soundscapes increases birds, heightens human experience and amplifies support for conservation.
Burgeoning urbanization, development and human activities have led to reduced opportunities for nature experience in quiet acoustic environments. Increasing noise affects both humans and wildlife alike. We experimentally altered human-caused sound levels in a paired study using informational signs that encouraged quiet behaviours in week-on, week-off blocks on the trail system of Muir Woods National Monument, California, USA to test if the soundscape influences both wildlife and human experiences. Using continuous measurements from acoustic recording units (n = 13) spatially distributed within the park, we found signs significantly lowered sound levels by approximately 1.2 decibels (A-weighted), thereby increasing listening area by 24% and bird availability by approximately 5.8% for every 1 decibel decrease. Visitor-intercept surveys (n = 537) revealed that our mitigation increased the number of birds perceived by visitors, rankings of soundscape pleasantness, and importantly, preferences for soundscape management. By lowering human-caused sound levels, we created an acoustic environment equivalent to a ~21% reduction in visitors. The positive feedback cycle we describe may lead to increased conservation support in a time when the extinction of nature experience looms.