Three representative neurons showing level-dependent modulation of frequency tuning by preceding noise (masker). The FLRFs of each neuron under different acoustic conditions are shown in each row from rows 1 to 3. The panels in the first column are the control FLRFs of neurons (A, B, and C) that were determined under quiet conditions. The panels in the second to the sixth columns are the masked FLRFs determined under various levels of masker conditions. The masker level (from a to e) from the second to the sixth column increased monotonically, as shown at the right bottom corner of each panel (in dB SPL). Panel D indicates the responses of these neurons to the masker alone. Panels E, F, and G represent the effects of preceding noise on MT, FLRF area, and CF, respectively.