Guessing the pressed keyboard keys by analyzing the audio from the microphone
Attempted to train it by typing for ~2 minutes. Basically typed everything on the GitHub page and tried getting predictions. 
Results were disappointing. I didn't see any accurate predictions. Even with the default p/q program I see mostly random results.I tested on a 15" Macbook Pro 2018 (latest version of keyboard that is softer to type of / less noisy)