Dischargae patterns of single auditory-nerve fibers in the cat responding to single tones were recorded and analyzed. Synchronization of the discharges to the stimulus tone was measured for frequencies below 6-kHz. The synchronized response and the average discharge rate each varied with stimulus level over 20--30-dB ranges. However, these ranges overlapped only a 10-dB range. Under certain conditions the average rate of response varied without accompanying variation in the synchronized response. The physiological implications of these observations are discussed.