The only reason they don't do that is because our devices aren't powerful enough to do it all the time.

I don’t disagree with you but the fact remains: they aren’t doing it.

A dedicated chip?

Yes?

I'm just glad we are not there yet.

Both iOS and Android show when your microphone is active so the whole conspiracy theory about it always listening to you and sending it back is pretty bullshit. And no one has yet found evidence of such network traffic either.

True, but the theory is far older than the indicators. So maybe Facebook stopped being sneaky once those controls came in? Not saying I believe them, but there's still room for doubt there.

Facebook doesn't have to be the one doing it - a 3rd party that controls an app on users' phones could be selling transcribed data to companies that want to run individually tailored ads on Facebook.

except it's always listening for you to say "siri" or "google assisstent". Some androids also show what music is playing nearby. You can thankfully opt-out but the ability to is still there.

They do that with local processing. For the music thing it calculates a hash locally and send it to their servers.

That still requires the microphone to be active, right?

Yes, but it doesn't record anything. It calculates a hash locally and sends that hash to their servers, where it is then identified.

Couldn't you do the same with tv shows and ads?

At least on iOS, not without hacking the operating system. Siri’s ability to listen for a wakeword without an microphone indicator requires privileges that normal apps don’t get. On Android, as far as I can tell, the same is true, except that some phones ship with preinstalled third-party apps which can then get extra privileges.

It runs on a specific coprocessor, even.

This seems very similar in principle to the perceptual neural hash that Apple created and uses to check every file on any Apple device. I recall that some people had an issue with that, because there is no guarantee what hashes will be added to the database, and no real way to know what file they will map. So, the hash could be anything, and could send anything, which is entirely up to the whins of whatever company or entity that deploys such a product. Effectively, this just means that you can in fact check nearly anything happening on an input, if it maps to some perceptual hash that is similar enough to one the server has in its db.

Actually there are no servers involved; it uses an on-device database:

> When music plays nearby, your phone compares a few seconds of music to its on-device library to try to recognize the song. This processing happens on your phone and is private to you.

https://support.google.com/pixelphone/answer/7535326?hl=en&s...

...They don't even need to hash content. Advertisers can just add ultrasound beacons to the audio track.

Imperceptible to human hearing, but readily picked up by a listening mic. In fact, there are static analysis tools for picking out apps that access such API's in FDroid, along with taking measures to feed said apps dummy data. At least for Android anyway.