Cox Media Group got kicked off Google's ad partner program a few years ago when 404 Media scooped that they had a feature called CMG Active Listening which did exactly this. They had a slide deck. Audio spying by advertisers is like doping in pro sports, everybody does it and you only get caught if you're stupid. Remember back in 2013 a whistleblowing NSA contractor told us to put our phones in the fridge if we wanted to have a secret conversation? He had a slide deck, too. The western world is run by a cult of pedophiles, the fact that our phones listen in on us without our consent is not a stretch.