What an amazingly silly (and fun!) thread... Well, obviously you're going to need a tried and true 'Bat Detector Pre-amp'... http://home.kabelfoon.nl/~bertrik/bat/preamps.htm What it appears he did was to use an audio range microphone and then tune the preamp to only amplify very high audio frequencies. I.e. - build a 100KHz pream with a high-pass filter at 30-40KHz... I didn't think you could have paid me to participate in this one... ;-) - Mark On Tue, 9 Nov 2004 16:26:11 -0500, Eric Dantan Rzewnicki <rzewnickie@xxxxxxx> wrote: > On Tue, Nov 09, 2004 at 11:58:54AM -0800, Erik Steffl wrote: > > mik wrote: > > >a certain jonathan segel <jsegel@xxxxxxxxxxxxxxxxxxxxxx> wrote: > > >>if you do end up recording bats, and slowing them into audio range, i > > >>for one would like to hear the files! > > >http://www.partnersinrhyme.com/soundfx/batsounds.shtml > > you (original poster, I don't have the first post anymore) might also > > consider other animals - small rodents, cats. Cats hear up to about > > 60kHz (that's what I remember, even if it's not the right number they > > hear a lot higher frequencies than we do), it was explained in the book > > I read that that's what they need to be able to hear the small rodents > > (so I guess small rodents emit sounds up to about 60kHz), plus cats use > > higher frequencies to communicate among themselves (that's why you only > > hear them doing the meow sounds when they are around humans). > > Ah!! very, very interesting. We have 4 cats. Communication above our > hearing range would explain alot about how they all seem to notice some > things at the same time and other collective behavior. And here I was > thinking they were telepathic. I'm glad I asked my original question. :) > > -Eric Rz. >
