Well, if you believe the stories appearing at the moment, the answer is almost certainly "yes".

A few years ago a attended an interview and the conversation found it's way to media players and voice activation. I made the fatal mistake of implying that such facilities were potentially of concern with regards to privacy given the potential for third parties to listen to and/or record conversations within range of the microphone.

They laughed at me. Conspiracy theories no-less!

Anyway, apparently there may be something to this with regards to Google;
https://bit.ly/31jvzZS

And possibly Apple;
https://www.theregister.co.uk/2019/08/02/apple_siri_no_conversations/

And last but not least, maybe also Amazon;
https://www.theregister.co.uk/2019/07/16/amazon_alexa_german_spying/

Oh, then maybe also Samsung ....
https://www.theguardian.com/technology/2015/feb/27/samsung-voice-recording-smart-tv-breach-privacy-law-campaigners-claim

(this is by no means an exhaustive list ...)

Anyway, my two takeaways from these stories are;

  1. Be aware of what you're saying, because you are probably within reach of an open microphone most of the time.
  2. Don't laugh at interview candidates. Firstly it is quite rude, but secondly, whereas you may (as usual) be right, there's always a chance the guy in the tin-foil hat is wearing it for a reason.

Incidentally, I found the instructions for disable Google voice assistant on my phone didn't appear to work, and "Hey Google" still continued to turn on the microphone. My only recourse appeared to be removing microphone permission from Google play services. Anyone find a better solution to this?