The development of hearing in the juvenile barn owl was investigated using tones (500 Hz to 12 kHz) and clicks of different rates (5-90 Hz). Auditory evoked potentials (AEPs) of the auditory nerve were recorded using the auditory brainstem response (ABR). Barn owl hearing matured in a similar trend to other developing vertebrates, including kittens, budgerigars, chickens, and gerbils. The onset of hearing began sometime earlier than the second week post-hatch, and proceeded in a frequency-dependent manner. Adult-like thresholds were reached in a progression from low to high frequency, and sensitivity was mature by P60. These patterns were consistent with CAPs recorded from juvenile barn owls in Europe. ABRs for clicks presented at 5-60 Hz demonstrated increasing amplitudes and decreasing latencies as barn owl chicks aged, while ABRs for clicks presented at 90 Hz were barely distinguishable between adults and juveniles.