Since most of our communication is estimated to be non-verbal communication (body language, facial expressions, tone of voice, etc.).
As someone who is deaf, I also depend on those clues and use it as part of the jigsaw when trying to understand what that person is saying.
But anyone can benefit from learning and being aware of the non-verbal communications that exist as it will make you a better overall communicator when you are conversing with anyone, not just those who are deaf.