https://www.casebriefs.com/blog/law/intellectual-property-la...
"Under California law, intentional imitation of a celebrity’s distinctive and widely known voice for commercial purposes constitutes tortious misappropriation."
Intentional is the key word here. So I presume that if you look like Emma Watson and go with your real name, you're fine. If you pretend to be Emma Watson, then it becomes infringing.