Echolocation of bats is a fascinating topic with an ongoing controversy regarding the signal processing that bats perform on the echo. Veselka et al. found that bats that use the larynx for producing the echolocating ultrasound have a stylohyal bone that connects the larynx to the auditory bulla. I propose that the stylohyal bone is used for heterodyne detection of Doppler-shifted echoes. This would allow very precise frequency resolution and phase-sensitive analysis of the returning echoes for determining the velocity of echolocated objects like insects.