Used to be, if you happened on a great tune on the radio, you might miss hearing what it was. Of course, now you can just Shazam it—let your smartphone listen, and a few seconds later, the song and performer pop up. Now scientists have developed a similar tool—for identifying dolphins.
Every dolphin has a unique whistle. Like this: [Dolphin whistle]. Or this: [Different dolphin whistle]. They use their signature whistles like names: to introduce themselves, or keep track of each other. Mothers, for example, call a stray offspring by whistling the calf's ID.
To tease apart who's saying what, researchers devised an algorithm based on the Parsons code, the software that mammals, I mean that fishes songs from music databases, by tracking changes in pitch over time.
They tested the program on 400 whistles from 20 dolphins. Once a database of dolphin sounds was created, the program identified subsequent dolphins by their sounds nearly as well as humans who eyeballed the whistles' spectrograms. The findings appear in the journal PLoS ONE. [Arik Kershenbaum, Laela S. Sayigh and Vincent M. Janik, The Encoding of Individual Identity in Dolphin Signature Whistles: How Much Information Is Needed?]
Seems that in noisy waters, just small bits of key frequency change information may be enough to help Flipper find a friend.
[The above text is a transcript of this podcast.]