The answer was probably both.
However right now Seth is very much wishign he had a voice because he wants to scream in excitement. It's been ages since he's gotten to communicate through sign language and not via his phone.

"No I can understand yours just fine! You have no idea how happy I am to find there's at least someone I won't have to communicate with via my phone, honestly it's really annoying that I generally don't get to communicate with the language I actually know!"