93% - 95% accuracy and it wasn't even a good quality recording

> When trained on keystrokes recorded by a nearby phone, the classifier achieved an accuracy of 95%, the highest accuracy seen without the use of a language model. When trained on keystrokes recorded using the video-conferencing software Zoom, an accuracy of 93% was achieved, a new best for the medium.

https://arxiv.org/abs/2308.01074

Notably, I believe this has to be tuned to each specific environment. The acoustics of your keyboard are going to be different from mine. Which is not much of a barrier, given a long enough session where you can presumably record them typing non password-y things.