And it made the magic system even less coherent. Polyjuice was described as physically changing your body to match the target, to the level of individual body parts changing one by one. Somehow excluding vocal cords from that is just not logical.
Not that Harry Potter magic system is well defined to begin with, but movies certainly made it worse.
The book polyjuice did change your voice, IIRC
Such a bizarre and unnecessary change.
And it made the magic system even less coherent. Polyjuice was described as physically changing your body to match the target, to the level of individual body parts changing one by one. Somehow excluding vocal cords from that is just not logical.
Not that Harry Potter magic system is well defined to begin with, but movies certainly made it worse.
If I had to guess, I’d assume it was to make it easier for viewers to keep track of what was going on.