[aesh2Xa1]

Cellular radios also have this capability. There's work done to track individuals in this way (matching your walking pattern/gait).

https://news.ycombinator.com/item?id=44416761

Signal processing is probably a general problem. This month we had news about transcribing speech from sound waves jiggling a regular computer mouse.

https://www.theregister.com/2025/10/07/mouse_microphone_secu...