@Baek Siyun FYI no one was picking a fight with you anywhere and you asked whether it was necessary to make the child deaf and why the author did that and I don't see the point of that question at all cuz WHY NOT? If the author wanted to make a character deaf, they can. They are free to do whatever they want with their own work. You don't have any right to question it. You ain't even paying for this. And if you wanted a biology lesson you should've said it lol or you could just google it since google is also free.