your phone gyroscope picks up nearby vibrations · footsteps · speech · table taps · mobile only · runs locally
why this matters
- mems gyroscopes in modern phones sample motion at hundreds of hz. above 80 hz they start picking up sound waves directly.
- gyrophone (stanford, 2014) showed that gyroscope-only access on android could distinguish spoken digits with surprising accuracy — without microphone permission.
- side-channel by design: phones expose motion as a low-permission api on the assumption it’s harmless. it isn’t — anything that vibrates the device leaks information.
- countermeasures: ios 12.2+ and modern android both gate motion behind a permission. this tool follows that prompt — say no on hostile sites.