Average duration of spike suppression as a function of NE tone duration and BD tone amplitude for all neurons. For every amplitude of the BD tone, the total duration of spike suppression increased as the duration of the NE tone increased. When the BD and NE tones were equal in amplitude (filled circles;r= 0.814; p < 0.0001), all points fell above the 1:1 line (straight line) showing that spike suppression persisted longer than the duration of the NE tone. When the amplitude of the BD tone was increased by 10 dB (open squares; r= 0.799; p < 0.0001), the duration of spike suppression decreased, but all points remained at or above the 1:1 line. When the amplitude of the BD tone was increased by 20 dB (filled triangles; r= 0.458; p = 0.0005), the duration of spike suppression was shorter than the duration of the NE tone at durations of ≥ 30 msec, where the triangles fall below the 1:1 line.