The ocean is a symphony if one takes the time to listen. The sounds of breaking waves, rainfall, or calving ice mix with humpback whale songs, snapping shrimp, and foraging reef parrotfish to create a unique chorus of frequencies specific to a given marine region. Recent research describes increases in anthropogenic noise pollution accompanying the rise in ship traffic and other human activities on, in or near the oceans, as well as impacts of such noise on marine mammals and coral reef health. By deploying hydrophones and fine tuning our recording devices, SEA Semester students document ocean soundscapes around the world. Specially-designed software is then used to visualize and quantify different soundscapes, allowing comparison between locations and over time. In each studied environment, acoustic measurements are augmented with visual observations of marine mammal behavior (e.g., breaching, blows, fluke dive), reef fish abundance and biodiversity, or vessel traffic.