Many years ago, I read a pretty bad science fiction story, about an inventor who developed a device to make supersonic sounds audible to humans. The guy went crazy when he found that trees and plants screamed when they were cut down. Anyway, do any animals emit sounds in the subsonic (below 30 Hz) or supersonic (above about 16,000 Hz) regions? Building a circuit to do this ought to be pretty simple-has anyone discovered anything interesting in these frequency regions?
African elephants are believed to communicate with sounds at the ~15 Hz range IIRC.
Edit: Ah, here’s something.
http://www.interspecies.com/pages/whale%20language.html
Beluga whales are capable of sounds well outside both ends of the human hearing spectrum.
It seems that rats laugh at ultrasonic frequencies.
Bats echolocate with ultrasonic frequencies.
Interesting? Nah.
Mice sort of sing at ultrasonic frequencies as well.
Leading to what was, hands down, the funniest moment ever on Wait, Wait, Don’t Tell Me.
That short story, by the way, was by Roald Dahl, and if I remember right, he didn’t exactly go crazy–he destroyed the machine after a tree tried to kill him.
All right, spill it.
First, nitpick. “Supersonic” usually is used to describe speeds higher than speed of sound - not sounds of frequency higher than humans are capable to hear. Proper term is ultrasounds. And “subsonic” means slower than speed of sound. Infrasound is sound of frequency lower than humans can hear.
Now, nitpicking done, I have played with bat detectors in the past. There is a lot of animals (mostly small) and things (like squeaking of folding paper) around. Lots of fun. Fortunately, we can’t hear them. Fortunately, because bats can be really loud, and we would have trouble sleeping with all that screaming around.
Warning to sensitive listeners: this episode features Mo Rocca doing his usual stammering hand-grenade-lobbing answer shtick.
(The bit in question occurs during the “Opening Panel Round” if you don’t want to listen to the whole thing.)
And let’s not forget about all those butterflies screaming and that annoying sound of the grass growing. It’s a jungle out there people, thank Og our spectrum of audible sound is limited. 
Well, there are squeaking moths, but they are rather quiet. Now bats are another story. In seeking mode they can crank up to 100 dB from their little muzzles. So much for the quiet evening at the park.
Nitpick senior moment for me–I knew instantly that supersonic was the wrong term, but couldn’t for the life of me think of what the appropriate term was–until I saw your post and the heaing myself say: “Duh”. :smack:
I have it at home, I’ll check it out tonight and post back the title.