N-Track Drums

I watched the EXCELLENT tutorial by Hotdogwater on setting this program up and I even tinkered around on my own and managed to import my own drum samples (just for the sake of doing it, not because I have some killer samples) but I cannot figure out what the little buttons are above the sample path field in the sound editor that say “learn” are.
There is a field above the buttons that look like you should be able to edit it, but I can’t.
When I press the “learn” button, though, the value in the field changes and the sound of the drum is all goofed up. Any info?