Here’s an interesting video from the Georgia Department of Natural Resources that provides a good overview of how scientists use a device called the “Anabat” to study the sounds bats make as they’re hunting.
From the Georgia DNR website:
The Anabat, a system designed to help users identify and survey bats by detecting and analyzing their echolocation calls is becoming a must-have device for wildlife biologists. Echolocation is what bats use to navigate and find food. Humans are unable to hear most of these sounds but the device picks them up, lowers the frequency so humans can hear them and with the aid of an attached PDA, the calls are displayed on a screen making it possible to “see” the calls.The displays are saved as files and can then be analyzed by the Anabat program once biologists return from the field. Certain bats have distinctive call patterns that can be read by experienced bat biologists. However, some bats produce very similar sounds, making the calls of some species hard to distinguish. Currently, researchers are testing systems that have been developed which use programs to identify the bat calls. These programs can make Anabat data more easy to analyze and useful on a much larger scale.While it is not always possible to identify each bat by its recorded call, biologists can often narrow the list of species down to a few that call in the same frequency range and are found in similar habitats.