The song, belonging to a humpback whale — a species beloved by whale watchers for its spectacular leaps — was captured in March 1949 off the coast of Bermuda. Just as significant as the song itself is the sound of the surrounding environment, according to Peter Tyack, a marine bioacoustician and emeritus research scholar at WHOI. The ocean of the late 1940s was significantly quieter than today’s waters, providing a starkly different backdrop to the whale’s vocalisations.

The recovered recordings allow scientists to follow whale sounds while reconstructing the oceanic soundscape of the mid-20th century. This preservation helps researchers understand how modern human-made noise, such as increased shipping traffic, affects cetacean communication. Research by the National Oceanic and Atmospheric Administration (NOAA) indicates that whales often vary their calling behaviour depending on ambient environmental noise.

This discovery predates scientist Roger Payne’s famous documentation of whale song by nearly 20 years. At the time, WHOI scientists on a research vessel were testing sonar systems and performing acoustic experiments for the US Office of Naval Research. Ashley Jester, director of research data and library services at WHOI, noted that while the scientists did not initially know what they were hearing, their curiosity led them to keep the recorders running. They even paused ship operations to ensure the clearest possible capture of the mysterious sounds.

The song was found last year during a project to digitise old audio archives. It was preserved on a plastic disc created by a Gray Audograph, a dictation machine common in the 1940s. While the equipment was crude by modern standards, it was cutting-edge for its era. Crucially, the plastic disc survived, whereas magnetic tapes from that period have long since deteriorated.