I doubt it.
If that was the case, tech researchers would have already detected issues and reported them to the press. Thus all of these “smart” devices that can listen are very carefully managed to ensure that when you shout “Alexa…” or “Hey Siri…” then — and only then — do they act on the sounds around you.
Can you imagine if it could be proven that Google, Amazon and Apple and possibly others were indeed listening in on users? And yes, I am aware of the fact that contractors routinely listen into audio passed into smart speakers as part of their debugging and development process but that is not the same as taking that audio and acting on what is heard to deliver targeted content. What kind of a marketing and publicity nightmare that would be… Speaking of marketing…
It is more likely you are talking about something that is very strongly marketed in your region and thus a topic of conversation and thus the ads.
I’ve heard concerns about this before but — from my own professional life and life experience — I know that regardless of what you think about what you talk about casually, chances are you and your friends are far more saturated with media from advertisers to begin with than you think.
For example, I have been looking for some old pieces of furniture hardware for the past few weeks. I have done searches on Google as well as eBay and even Etsy as a part of my research. Do I now see ads for such hardware on my phone when I do other things? Nope.
In contrast, a few years back there was a very big marketing push for the nutritional supplement known as Huel. I did some basic searching for what it was but not very deep. But when I was bullshitting with some co-workers, I joked about Huel and when they themselves went to a news site, suddenly they saw ads for Huel…
And then a few days later I saw a few unopened bags of Huel on someone’s stoop in Brooklyn and was minority flipped out… But then I realized: I live in a major U.S. city, there is clearly some marketing push for this item and thus ads all over the place.
As for the ads my co-workers and I saw, again my co-workers and I are the perfect target market for some gunky “meal as a drink” product. Thus if places like Facebook and Google already know who we are demographically and know we search for tech stuff from time-to-time, then we would be targeted by ads for that product.
At the end of the day we all have freewill and the ability to make our own decisions. But in a media saturated world, we are utterly soaked in targeted advertising that — no matter what you think — enters our mind and influences us.