This probably could explain most people's accounts of this, but I've been approached by companies who offered large lump sums to include their SDK which required microphone access in our mobile app, in order to fingerprint what our users were watching on TV while it was open, nominally to see what ads they were seeing. I wouldn't be at all surprised if they or others were going a good bit further than that and trying to run speech recognition on overheard conversations, unless it's illegal somehow.

AdTech is frankly a revolting industry.