What I dislike about this is that you seem to suggest that it would have ever been a possibility for the Development team. They can scarcely draw out content, and you're checking up with them to see if they modified every piece of existing voice acting script for the sake of a single cosmetic piece.
I hope that trip was part of your coffee run or toilet break, or something.
It could be accomplished through SFX filters, might be something for the future. I remember when the game was first released people thought the masks was changing their voice.