Thank you for the kind words 😄
The accuracy mostly depends on your microphone quality and how noisy your environment is. I tried to make it more adjustable through the config file, where you can change the tolerance settings. If I remember correctly, the default tolerance is around ±5 Hz (though I might be wrong 😅).
Faster typing is technically possible — it only needs around 200 ms to detect a frequency, but I honestly wouldn’t recommend it. I tried typing quickly myself and it was pretty painful.
And yeah... you’re right, it probably shouldn’t work, but somehow it does. I was mostly just bored, and when I’m bored I tend to build weird stuff like this.
The main inspiration was a video by Code Bullet where he recreated Guitar Hero using an actual guitar and used frequencies to control his mouse and type. That video basically made me think: “what other dumb but interesting thing could I build with frequencies?” 😄
If you want, here is that video.