A paper on the sonar capabilities of bats.
This paper deals with the two different kinds of sonar techniques employed by bats throughout the world. The author further discusses bats that don’t use echolocation at all. The author then examines the conflicting studies that have been done on this biological phenomenon and explains how the process works.
Burton (1982) states that the majority of the Microchiroptera utilize FM based echolocation. In this type of echolocation the pulses of sound, or calls, last no longer than a few thousandths of a second and drop through nearly an octave. The few species that do not use FM echolocation utilize the CF based echolocation. With CF echolocation the calls last up to ten times longer than those of the bats that use the FM method, explains Burton.