It really depends on so many things. Some are done at the CDN level just for you, others are done at the CDN but for everyone, others are baked into the streams from where they originate from. Without knowing which channels or how you are consuming them its hard to say. If its local "radio" stations with a streaming version of their on air things, I have always heard the same ads that the on air FM gets when being subjected to them around the office.

As richms says, it really depends. One thing I think he left out is how much the advertisers know about you based on the digital exhaust you leave behind online. Did you switch devices recently or reset your advertising ID recently?

I sometimes travel to AU, download pod casts over there and in the following week, back here, I'm surprised by an ad that is obviously targeted towards AU. At other times, I downloaded the same episode again and it contains different ads. They ad lest have gotten better these days & don't cut a presenter off in the middle of a word.

Looking through the episode notes themselves, I found https://pcm.adswizz.com/ for example.