The Baton is a simple but versatile “frequency division” bat detector that allows the listener to hear the ultrasound produced by echolocating bats. The Bat Baton is sensitive to frequencies from 20 kHz to 120 kHz. It has a division factor of 10, meaning the sounds of a 50kHz bat is reduced to only 5kHz—well within the range of human hearing! These calls are captured through the microphone located at the top of the baton, and then emitted through the front-facing speaker.
Baton
The Baton is a super easy to use and inexpensive frequency division detector that can be used to monitor bats by itself, or attached to a laptop to view a live sonogram.
Pettersson D230
A combo heterodyne and frequency division detector. Using stereo headphones, you monitor the bat's full frequency range in FD in your right ear. When a bat arrives, quickly tune the HET (which you hear in your left ear) into the strongest signal. The frequency on the display will be where the bat's is calling the loudest, and is a huge step towards identification.