For those who may come after...
N has the ability to read a WAV file as many times and on as many different tracks as you like. Cloning the applause track, and then shifting the clone (Ctrl-click-drag) will in effect lengthen the applause.
You can also Copy/Paste (Ctrl-C, Ctrl-Shift-V) a part within a single track. This basically duplicates the part (WAV) and adds it to the end. So N simply plays the WAV over and over again.
tj