Ornithol Sci 5: 15–22 (2006)

We review recent studies that examine the temporal resolution of the avian auditory system as measured behaviorally in a small songbird, the Zebra Finch (Taeniopygia guttata). These birds naturally learn and produce complex harmonic vocalizations. Here we created complex harmonic stimuli that simulate the fine temporal properties of these natural calls in order to probe the possible parallels between productive precision and perceptual acuity. The studies we review show that these birds are exquisitely sensitive to changes in temporal fine structure in complex sounds, 3–5 times more sensitive than humans, and probably other mammals. This sensitivity also was obtained with several types of synthetic harmonic stimuli that mimicked particular properties of natural signals, including harmonic sounds with individually altered components, Schroeder-phase complexes that control for envelope cues, and synthetic signals constructed from repeated single periods of natural calls. These last studies confirm that Zebra Finches are capable of discriminating among their species-specific vocalizations using only changes in temporal fine structure—something humans, tested on the same stimuli, cannot do.