There’s no logic in Boba’s real voice coming out of the helmet at all. If you were the most feared bounty hunter in the galaxy, you want to be able to lose the suit once in a while and be incognito in public.
I say it even breaks one of the Cardinal Rules of the Star Wars Universe: that wearing a cool-looking bucket on your head changes your voice. Darth does it, Leia does it, and Boba ostensibly did it since his voice sounded awesomely processed and mechanized.
The makers of TFA get it, and lampshade it with Poe’s nice dig at Rilo Kiley about it being "hard to understand [him] with all the–apparatus…