World of Ultrasound
It was as recent as 1940 that it was first stated that bats used ultrasound for location and hunting. Even then the idea was dismissed as a fanciful idea in some learned quarters.
Handheld bat detectors have only been available and affordable for a decade or two, but now many bat enthusiasts have discovered the World of Ultrasound that has been unknown to the human race for millennia.
Bat detectors are indispensable for amateur and professional alike and are an indispensable aid to identifying bat species. However they are only an aid as other clues are often needed for a positive identification.
The following bat sounds were recorded with the most common and simplest type of detector the heterodyne detector
Click on the images for the sounds.