Research in my laboratory of comparative psychoacoustics is aimed at understanding how animals communicate with one another using vocalizations and whether there are parallels with how humans communicate with one another using speech and language. Like humans, birds such as songbirds and parrots rely on hearing and learning to develop a normal vocal repertoire. We often study budgerigars, canaries, zebra finches, and other small birds because they must learn their species-specific vocalizations - a process that bears some similarity to how humans learn speech and language. Past projects have included vocal learning and vocal development in budgerigars, how hearing loss affects vocal learning and production, whether newly regenerated auditory sensory hair cells result in a recovery of hearing and vocal behavior, and how noise affects hearing both in the lab and also in natural environments. We are currently examining the extent to which birds listen to the sequence of syllables in their song (much like humans listen to speech) or whether pay more attention to the subtle acoustic structure of the song syllables. Somewhat surprisingly, we have found that the message is coded in the acoustic fine structure of these complex sound syllables and not in the sequence of syllables. Moreover, birds are hearing these subtle differences in timbre in their song syllables well beyond what the human auditory system is capable of perceiving. In other words, avian acoustic communication may be much more sophisticated than we previously thought.
