How can we communicate with a blind and a deaf person?

https://lemmy.world/post/205542

How can we communicate with a blind and a deaf person? - Lemmy.world

Someone posted how can we communicate with a blind person as a joke but got me thinking how is it done with both blind and also a deaf.

A famous example of a deaf/blind person is https://en.wikipedia.org/wiki/Helen_Keller - this article contains some explanations about how she was able to learn to communicate with the world.