My parents are both profoundly deaf. My brother and I have normal hearing. My parents never wished for us to be deaf and were delighted to find out that we weren't. This came from their experience growing up that a disability, even one as manageable as deafness, is disadvantageous in our society.
When my parents were growing up, deaf schools concentrated on trying to get deaf children to speak properly (almost impossible if you have no hearing) and to lip read. Very little effort was made to develop academic aptitude. My mother was told it was pointless for deaf children to do 'O' levels, despite being an incredibly intelligent woman and that her dreams of working in a bank were impossible. My dad has a similar story to tell.
When they were growing up, people still imagined deafness to be associated with sub-normal intelligence. TBH, I think many people still do think this about people with disabilities, full-stop.
I share this with you to give you an insight into what Paul might be feeling. The world punishes people for not being perfect. Even his own mother, in his eyes, refused to accept him for what he was and still cannot communicate with him in the way he prefers. I think Paul may have wanted his child to be deaf so that it would be a part of his, accepting world, and not the world that he grew up in.
My mum and dad took the opposite view. Their ambitions were stifled because of their disability and they wanted more from life for my brother and I. We grew up using BSL at home - I learned to sign before I could talk.
Don't be too hard on Paul's mum. She was given advice by the professionals in the field at the time. My dad's parents were told exactly the same. She wanted to do the best for her son and she was told that encouraging him to sign would not be the best thing. It's not her fault.