[LAU] Alligning audio without graphics (for phase inversion cancellation)

Hey hey, it's easier to describe the problem I think. I hae two pieces, one the song with vocals, the other the exact same song, but only the instrumental. Now I'd love to isolate the voice by alligning them and mixing them with one having inverted phase. Since I can't see, and apparently often instrumentals don't start at exactly the same time, I need a way to synchronise those tracks. time shifting by hand is very tedious and hasn't yet yielded a perfect result. There are other issues, which can cause "confusion", so I'd like to get this one out of the way. Does anyone know of a way to do it from the commandline? Sometimes alligning the beginnen of a piece (the onset of sound) might do, but sometimes it's a little more complicated. Anything from Sox to Csound will do. :) I appreciate any hint in the right direction! Thank you! Ta-ta ---- Ffanci * Homepage: https://freeshell.de/~silvain * Twitter: http://twitter.com/ffanci_silvain * GitHub: https://github.com/fsilvain