Voice of Batman

https://www.youtube.com/watch?v=lTYHK0t_GpQ

1. Audacity, record some talking
2. ctrl + d to duplicate track
3. on top track effect/change pitch, set percent change to -16
4. bottom track, same thing, but do -20
5. maybe select all (ctrl + a) and effect/change speed, set speed multiplier to 0.95
6. maybe some sort of compressor on everything