Day in day out, most of us walk around with a microphone, camera, and GPS tracker in our pockets. They may not be tracking our every waking (or sleeping) second, but our phones are creating enough metadata that if linked together it would help anyone glean a crisp portrait of our daily lives.

Since the advent of voice assistants like Alexa and Siri, allowing technology the levels of access where they’re constantly on high alert, waiting for the signal to spring into action is fast becoming a cause for concern. Just this week, a US judge has requested access to an Amazon Echo, thought to be the main witness of a double murder, because prosecutors hope the Alexa software (which was sat on the kitchen counter at the of the incident) will reveal audio of both the killing and disposing of the bodies.

But Alexa keeping track of our commands is only the tip of the iceberg. Last Sunday the British newspaper The Observer revealed a whole host of new patents filed by Amazon and Google show their technologists are looking to develop more sophisticated ways of understanding human behavior (listening to our conversations constantly, collecting inferences—humidity, temperature and light levels) to gain deeper insights into our daily lives.

If that isn’t scary enough, a new study by engineers at Case Western Reserve University shows how smart home appliances can monitor the changes in vibrations, sound and electrical field in a home, revealing our every movement. “We are trying to make a building that is able to ‘listen’ to the humans inside,” said Ming-Chun Huang, co-author of the study.

Called the “Internet of Ears”, the concept is about looking at metrics other than audio to record or measure how people live. “There is actually a constant 60 Hz electrical field all around us, and because people are somewhat conductive, they short out the field just a little,” said another of the researcher’s behind the study. “So, by measuring the disturbance in that field, we are able to determine their presence, or even their breathing, even when there are no vibrations associated with sound.”