Being deaf means not being able to hear. But the deafness is not an unambiguous concept. It is not just a matter of not being able to hear.
Being deaf since early childhood, profoundly deaf, means that sign language is your first language.
You have never heard Swedish spoken. From sign language profoundly deaf learn how to read and write. In 1981 sign language was acknowledged as the first language of the profoundly deaf. In Sweden there are between 8.000 and 10.000 profoundly deaf persons.
If you have become deaf in adult age, deafened, Swedish is your first language. You speak, read and write without difficulty. The difference between being profoundly deaf and deafened is very great.
When the word deaf is used in the text, we refer to profoundly deaf.