Something similar to it happened in 2019. A man became completely paralyzed, but retained his senses. With the help of medical experts, he learned to control his level of brain activity. A computer monitoring his brain activity produced an audio tone which would rise or fall corresponding to his activity level. Soon he was indicating “yes” or “no” to letters. One of his first sentences: “I love my cool son.”
I feel like one of my first sentences in these situations would be "Morse code". Granted, it's not strictly binary, but there's gotta be a way to make it work.
Source:
https://www.technologyreview.com/2022/03/22/1047664/locked-i...