So in the second movie, the movie where they break into the ministry(I forget what movie it is), and the 7 Potters scene. What do they all have in common: Polyjuice Potion. And no matter who they are looking like, they still keep their original voice like in the 7 Potters you hear Fluer actually saying something with her real voice as Harry. HOWEVER in the fourth movie Barth Crouch Jr. sounds just like Mad-eye Moody. So why didn’t Crouch sound like himself when everyone else did?