Responses

He probably can speak, like make sounds, but feels awkward and selfconcious talking because he lost his hearing not too long ago... so he prefers not to speak

Have you ever noticed when you're in a really loud area, like a concert, when you speak you aren't sure if you're making sense, or if you're even saying the right words? I think that's how it is with deaf people. Since speech and hearing is sort of connected, being unable to hear makes it harder for them to talk properly
I really love this manga, but I kept wondering why the deaf man didn't talk. He only lost his hearing a year ago, so shouldn't he be able to speak?
I mean, a lot of the people I know who were deaf from birth can still talk; it just sounds a little different than typical speech.
So... I'm genuinely curious as to why the mangaka doesn't have him talk.