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.
The teacher would also out helen keller’s hand on the teacher’s face so helen could feel throat vibrations, the way the lips moved. Because of that, helen could actually talk (even though it sounded a little strange). You can youtube her speech
There's a pretty decent movie about it, based on the book she wrote iirc. It's a little older, but still pretty good and her experience is definitely interesting, and speaks to the ingenuity of survival.