Apple recently spent $2B to bring subvocalization inference to iPhones, from the inventor of FaceID and Kinect, https://www.newsweek.com/apples-2b-ai-acquisition-could-have...

> users [could] interact with Siri and future Apple devices without speaking out loud.. AI systems capable of interpreting facial expressions and subtle muscle movements to understand so-called “silent speech.”

I’d love a 2015 input system that worked, but my iPhone’s keyboard prediction has been broken for like a year.

Have you looked into Shokz? I use these a lot, they seem like working bone conduction headsets to me.

https://shokz.com/pages/openrunpro2