Human ears were stimulated by 2‐min 20–105 dB sound‐pressure level continuous tones, and postexposure thresholds were examined for other tones that were variably related in frequency to the exposure stimuli. Each test tone (250, 1000, and 4000 Hz) was paired with exposure tones of the same, half, and twice the test‐tone frequency, as well as with a 50‐Hz tone and a tone of considerably higher frequency (4000–10 000 Hz). The postexposure patterns of threshold sensitivity that resulted from such procedures ranged from momentary auditory sensitization to configurations dominated by auditory desensitization. The logic of this sequence of behavior in light of known synaptic activity is discussed.