In addition to bat detectors, there are also bat call recorders or loggers. These can be small hand-held devices or are left static in a suitable place (sometimes for long periods) to monitor bats. The bat calls are usually recorded onto SD or similar memory cards. The more sophisticated recorders will also provide more information about where the bats calls were recorded, such as the temperature at the time and the GPS co-ordinates to provide the exact location.
The recordings can then be downloaded to a computer and analysed using suitable software to determine the call characteristics and hence the species of bat or bats. This analysis will generally reproduce the bat call graphically in the form of a sonogram which may look like this:-