My late sister in law was born what was then termed as 'partially deaf' ... she used two hearing aids with wires and a contraption strapped to her chest. Without them she could hear virtually nothing. Her primary school sat her at the back of the class with a colouring book as they believed her to be 'of low intelligence'. This was the 1970s ... not the Dark Ages. In reality she was bright as a button.
At the age of seven her parents were persuaded to send her from her large and loving family to a boarding school for the deaf near Brighton

. When her big brother and I visited her we discovered that the 'partial hearers' like her were not allowed to use sign language as the 'totally deaf' did and indeed if they did so they were punished. Despite our protests nothing could be changed.
She picked up a little BSL from watching, but not enough to be of any use, but with the old fashioned hearing aids available at the time, unless someone was close by and speaking directly to her so that she could lipread she could understand very little of what went on around her. She did well academically but socially she was very isolated.
Of course, as technology improved she was able to hear more and her speech improved, but her life wouldn't have been as sad and isolated as it turned out to be had she been taught BSL and felt part of a community rather than being permanently if unintentionally excluded from most of what went on around her.
So so sad.