A crackling recording from March 1949 captures a nearly howling sound. It's a humpback whale singing in the waters around Bermuda. The recording is the oldest known and was discovered last year by researchers at the Woods Hole Oceanographic Institution in Massachusetts, USA.
The recording gives researchers an opportunity to study both the song and the surrounding sounds, says Peter Tyack, a researcher at Woods Hole.
It shows us what the ocean sounded like in the late 1940s. That is otherwise very difficult to recreate.
With the recording, researchers now hope to study whether and how whale songs have changed with increased human impact on the oceans, such as increased shipping.
