Spike suppression and offset facilitation in a short-pass neuron as a function of BD tone amplitude. Increasing the amplitude of the BD tone from +0 to +30 dB with regard to the NE tone systematically decreased the period of spike suppression from 23.9 msec (A) to 17.7 msec (B), 17.6 msec (C), and 7.9 msec (D). Note that spike counts increased above baseline when the BD tone (or pedestal) occurred at or near the offset of the NE tone (or composite stimulus), suggesting response facilitation. Spike count and latency plots are as in Figure 8A. BD tone duration, 2 msec; NE tone duration, 20 msec; BD and NE tone frequency, 31.5 kHz; BD tone threshold, 25 dB SPL; BD and NE tone amplitude, 35 dB SPL; 10 trials per stimulus.