Felleisen rhymes with:
bison, bryson, dysan, dyson, eisen, eisin, geisen, hyson, neisen, nicen, reisen, theisen, theissen, thyssen, tyson
Felleisen sounds like:
falcigno, falcon, falcone, falconi, falsone, falzon, falzone, faulcon, feliciano, filson, flagman, flagmen, flashgun, flaxman, fleischman, fleischmann, fleishman, fleshman, flexion, folkman, folsom, folson, fulgham, fulghum, fulsome