Measured RTs in relation to 2 regular preparatory intervals (PIs) within 3 stimulus intensity levels. The intensities were set at approximately the 75% absolute threshold, the 100% threshold, and at a much higher level for each of 48 undergraduates. This corresponded to approximate mean db. levels of 6, 8, and 81, respectively. The PIs were .5 and 6 sec. RTs were found to decrease with increased intensity and to be related to the PI in the usual way only in the 2 higher intensity conditions. The combination of the lowest intensity tone and the least time to get set for it made for the very slowest RTs. Inter-S variances were large in the condition of lowest intensity stimulation. (PsycINFO Database Record (c) 2006 APA, all rights reserved)