Adult birdsong is actively maintained by error correction

Abstract

Young birds rely on auditory feedback when learning to imitate the songs of adult birds. Here the authors find that, as with humans, birds use auditory feedback to correct vocal errors in adulthood. This suggests that lifelong error correction may be a general principle of learned vocal behavior. Humans learn to speak by a process of vocal imitation that requires the availability of auditory feedback. Similarly, young birds rely on auditory feedback when learning to imitate the songs of adult birds, providing one of the few examples of nonhuman vocal learning. However, although humans continue to use auditory feedback to correct vocal errors in adulthood, the mechanisms underlying the stability of adult birdsong are unknown. We found that, similar to human speech, adult birdsong is maintained by error correction. We perturbed the pitch (fundamental frequency) of auditory feedback in adult Bengalese finches using custom-designed headphones. Birds compensated for the imposed auditory error by adjusting the pitch of song. When the perturbation was removed, pitch returned to baseline. Our results indicate that adult birds correct vocal errors by comparing auditory feedback to a sensory target and suggest that lifelong error correction is a general principle of learned vocal behavior.