Ask HN: Is it true our phones listen to us?

I heard about this theory quite a lot, many people around me have reported similar stories: they talk aloud with someone (e.g. in a bar) about a topic with their phone nearby, then when they open their phone they will notice some ads about that specific topic. For instance, a friend reported they were talking about a singer and when he opened Instagram he add an ad for the upcoming concert of that singer although he didn't search for it. Someone even told me he mentioned a city in a conversation and when he opened Google Maps, the view was on that specific city.

I have never noticed this behavior myself, and I saw a video from a youtuber saying that these theories are strange since analysing voice on the device is complicated because first, until recently it was not so obvious, and second, it requires a good amount of computing power. Analysing the data on a server is even harder given the huge amount of users. Current progress in AI could make this work for sure, but still, I'm a bit skeptical. Going back to my examples, I guess the guy that got the ad for the concert was following the singer's account? And the other may have looked at google maps but doesn't remember it?

I'm not trying to say all these testimonies are wrong, but given the awareness in the population that phones are literal data sinkholes, sometimes it feels like we tend to believe in some far-fetched stories.

Did you experiment similar stories? I'd like to ear your opinions.

Thanks!