…within reason. I know that the top answer will be to flash a different OS on your device. A lot of us are not at that point right now.
So I was texting with my wife in Spanish and suddenly a system bubble popped up, “would you like to translate this to English?” At a minimum, this means that Google is reading the words on my screen at all times to detect the language. I don’t know if this is possibly done on device, but translation certainly isn’t. I’ve already changed my system translation app to Translate You.
I’ve noticed other times that Google watches or listens in the background. It has a feature to detect ambient songs playing, for example.
What other standard settings should I check for to prevent Google from watching and listening to my phone in the background?
As long as you know the real answer already.
Do a factory reset on the phone, disable EVERY app you don’t want to use (app info, disable works in modern AOSP even for apps you can’t uninstall like youtube)
Don’t link your google account to the phone.
Test your phone by saying “OK Google” and making sure it doesn’t respond.
Slowly install the apps you want / need, testing the “ok google” and spanish text to see if it triggers some data-scraping service.
interesting idea, would test on an old device or spare device before wiping my phone though, you may not like the results and puts you back at square one with all your stuff gone and have to reset it all anyway.