It can't selectively listen. It processes all audio input for those key words. Once it hears the keyword, it then sends a recording of what you say next to a server.

This is not accurate. At least on the Google home the "wake word" is baked into the hardware and no audio gets through that piece of hardware until the wake word is detected.

Obviously there can be defects, but Google is not getting 100% of the audio from your home.

I highly doubt the 'wake word' is embedded in devices on a hardware level rather than software. That sounds like a terrible idea on multiple levels.

You are using 'Google' in a vague way which may be why you are confused about what my comment meant. The Google device gets 100% of audio it hears, because it can't magically hear a 'wake word' without listening to all audio. It only sends audio to a Google server after the wake word.

Aren’t “OK Google, hey Siri, hey Alexa” all processed/recognized locally? Otherwise, it would be a horrible idea to send EVERYTHING off to the internet for processing. Not even concerning privacy issues, it would just be unworkable that way.

(This is at least true for the iPhone, Hey Siri is recognized locally before anything is sent off to the net)

Re reading your comment, I guess you mean: the sound processing goes through the local microphone no matter what, even if the audio is only forwarded on if they lead with certain keywords, right? In other words, just like how every other voice activated system has to work. The privacy implications are that the equipment could be compromised to actually put the recording in longer term storage, like a bug or something.

There’s a ton of accidental triggers. Digging through my Alexa history was eye opening. I got the idea to go looking from this article: https://www.fatherly.com/love-money/amazon-alexa-made-an-acc...

Yes, that's exactly what I meant.

Officially, no, but it's not uncommon for it to misinterpret another word as the wakeword and then capture and send off 30 seconds or more of audio that was never intended for it.