
Your grandpa is impressive. Is he deaf from baby born?
I used to had a deaf neighbor. She can't speak. I told her she can because she only can't hear. But when she let out the sounds it's not word and because she never hear sounds she doesn't know how to let out sounds. She speak with sign language. Btw she isn't the only one I met that is deaf. All the deaf people i met can talk as well (I think it must be something like connection between ear & vocal cords) idk I m not a doctor. But that is base on my experience. And another one, I have a friend with a dad who just recently deaf, one ear, so he can speaks normally

Yeah a lot of people who are deaf can talk...but it takes effort and its often distorted...depends on how long they've been deaf, and just the individual.
Its often easier to just sign takes less effort...and they're often more confident in their ability to sign. Your grandfather is maybe just more experienced at talking, has more practice, or he's more confident in his ability.
It just depends on the individuals' circumstances.

I think it's usually the longer you're deaf the better you are at it. My guess is that he built up the skill because 60 years is a long time to learn and practice. I bet if you talked to him twenty years after it had happened he'd sound different. And it might help that he wasn't born deaf...I know that it takes a lot of time but I'm not sure if it's harder if you were born deaf or not. I met a girl once who'd been deaf since she was a little girl, and she spoke as well as me, but I don't remember if she'd been deaf since birth, or if it happened when she was just really little. I dont remember.
I know that my cousin went deaf as an adult...and had been deaf like 20? Years or about that, and she could talk but it was very distorted. It was easier for her to just sign, or finger spell, or write.

Your grandpa is great. I knew another girl who wasn't born deaf and she just recently lost her hearings like 2 years. She uses sign language and I heard she spoke before, her voice sounds distorted because she can't hear her own voice. She doesn't know if she saying too loud or too soft. It depends on the individual and practice just like KikiBee said, but most deaf people I met aren't speaking, they prefer note or sign language. Not everyone are same :)

When i was reading all your comments, which is true. Because i was born deaf person but i have cochlear implants. I have a hard time to speaking and hearing. Most deaf people want to be act like a normal person. Some deaf people get really scare and shy because Shehe don't want everyone to know shehe was deaf. i am always shy and scare when i meet new people but it is take a while to know them for a month. (●'◡'●)ノ i love this manga lol
Ok before any of you get mad or said anything don't get me wrong I love the story it just that he is deaf , but he can still talk I don't see why he have to write or sign. I just don't get it I mean I have a grandpa that is deaf and he can talk just fine and we can still understand fine. I mean he can't hear us we have to write to him but he can talk back to us not sign or write to us.