Echolocating bats rely on audiovocal feedback to adapt sonar signal design

Significance Echolocating animals are well known for their capability to extract rich information about the environment from echo returns. However, past research has not determined whether audiovocal feedback contributes to sonar call design. Audiovocal feedback is the process whereby an animal listens to the sounds it is producing and is used by both nonecholocating animals and humans to control their ongoing vocalizations. Here, we show that echolocating bats rely on audiovocal feedback, instead of echo feedback, to adapt their sonar call design in response to acoustic jamming signals. Our findings demonstrate that bats, like birds and humans, not only use audiovocal feedback to fine-tune the features of their calls, but also do so on a rapid timescale. Many species of bat emit acoustic signals and use information carried by echoes reflecting from nearby objects to navigate and forage. It is widely documented that echolocating bats adjust the features of sonar calls in response to echo feedback; however, it remains unknown whether audiovocal feedback contributes to sonar call design. Audiovocal feedback refers to the monitoring of one’s own vocalizations during call production and has been intensively studied in nonecholocating animals. Audiovocal feedback not only is a necessary component of vocal learning but also guides the control of the spectro-temporal structure of vocalizations. Here, we show that audiovocal feedback is directly involved in the echolocating bat’s control of sonar call features. As big brown bats tracked targets from a stationary position, we played acoustic jamming signals, simulating calls of another bat, timed to selectively perturb audiovocal feedback or echo feedback. We found that the bats exhibited the largest call-frequency adjustments when the jamming signals occurred during vocal production. By contrast, bats did not show sonar call-frequency adjustments when the jamming signals coincided with the arrival of target echoes. Furthermore, bats rapidly adapted sonar call design in the first vocalization following the jamming signal, revealing a response latency in the range of 66 to 94 ms. Thus, bats, like songbirds and humans, rely on audiovocal feedback to structure sonar signal design.