If you have not yet imported your audio files, do so now {File> import}. If there is not already a keyframe on frame
one, add one from the insert menu {Insert> Keyframe}. In the timeline, double click on the keyframe
you just added, or highlight the keyframe to open the Frame Properties
dialogue box {Modify> Frame}.
Click on the sound tab. Your imported audio files should all appear
from the pull down menu. Select your drum track. Set the sync
method to "Event" and enter a loop value of 16 (this can be changed
later).