Page 47 of TY3 manual mentions creating custom drum voices via importing .wav files.

While not detailed it looks a similar method to that on Ty2 where you can import wav files into Voice Creator, use them as elements (up to 8) in a custom voice and then carry out various edits including key assignments, velocity triggers etc. According to Ty2 manual the Voice Creator can recognise loops- up to 1 per audio file.

John