Music
Ambience: Mouse song slowed down
Here’s a news flash for you – Mighty, Mickey and Minnie have turned in their union cards. Apparently they’re not the only mice that can carry a tune. I’m Jim Metzner and this is the Pulse of the Planet. Dr. Timothy Holy is a professor of neurobiology at Washington University in St. Louis, Missouri. While doing some experiments with the rodents, he came to a surprising revelation: mice sing. We’re listening to some slowed down recordings.
“It had been known for a long time that mice make a variety of sounds, some of those are audible to our ears-the famous mouse squeak is one such example. But mice also make sounds up in the ultra-sound, at frequencies too high for us to hear. And, while that was known for a long time, the specific characteristics of the sounds hadn’t been studied very carefully, at least not using sort of modern equipment and modern methods of analysis. And so when we just looked carefully at the sounds they were making, we discovered that they were a lot more interesting than we expected.
We actually made them audible in two different ways. And so the easiest way is just to play them back more slowly; anyone whose played back a record more slowly than it was meant to knows that the pitches also get lower when that happens. And so that was the first way that I ever heard these, heard these sounds. The nice thing about that is that you can appreciate the individual varying sounds that the mouse makes when you slow them down. But what’s really hard in that case is to get a sense for sort of the cadence of the song. And so the analogy to bird song became much clearer when I wrote some software to shift the pitch, but not change the speed of the playback, sort of in the way that a musician might transpose a piece of music.”
Perhaps you’re not convinced that these vocalizations qualify as real songs. Well, you’ve got to tune into our next program. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.