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.

Look into Hellen Keller and how she learned. I’m not 100 percent brushed up on it but I do know it involved touch and feeling. The teacher would trace letters onto her hands and also use temperatures and textures to convey meaning to her.

There’s a few different ways. If the person is mostly/fully deaf and blind, then communication is primarily through touch sign language interpreter (signing on the person’s hand) or a device that you type into that outputs braille for the deafblind person. Some deafblind people are not fully deaf or blind and can see sign language if the interpreter is very close to them.

still drums. vibrations.

I have actually dealt with a partial deaf blind student back in elementary school.

You can sign ASL into their hand so they can feel what you’re signing(normally individual letters). Or they hold your hands to feel the gesture/sign you’re are making.

They read braille as a just a blind person would.

But over all takes more effort to learn this way.