Some modern sound cards can sample at up to 190khz. That gives you a max detection frequency of 96khz. The first hit I found on google says bats go up to 100khz. Close enough.
LoL, yea I know, but wanted to be sure that they are not talking about me
well I was think about a circuit which is able to mulitiple the comming freq by 2 or 3 and perhaps devide it by 2 or 3! no I am not taliking about heterodyning, but something like a chip which is able to convert the audio and ultrasonic spectrum...