Earlier quoted context omitted.
> People have. And it's always shown that no apps are opening your mics when you're not using the app, and that if you're using the app they generally will only open your mic when it makes sense to do so. Can you link to people who have checked? I had a couple of the last BlackBerry phones, that ran Android. They came with this "DTEK" [1] app that monitored when apps accessed your phone's sensors. And I remember ever…
https://futurism.com/the-byte/phones-listen-theory-debunked https://www.youtube.com/watch?v=CVazBWGgg64 They're sending pretty much everything BUT audio. Main reason is that audio is just tremendously inefficient compared to other signals. It's large and expensive to store and process and doesn't really give you that many bytes of information you can't get elsewhere for how expensive it is to handle.
Could have a delay. Could only work when physically moving, indicating activity. Could only be activated for some user profiles based on usage patterns. Could only activate for device owner's voice, like the voice assistants.
I used to think audio would be prohibitively expensive for Facebook to eavesdrop. But they could easily sample at random, compute it on-device, then only send keyword hashes. I think it's much more technically feasible than you're giving it credit.
I agree they probably aren't. Most likely, they predict using their other spying, then people notice frequency illusion/coincidence. But I find it odd nobody's checked.