I found that the voice of the speaker impacts my comprehension quite a lot. Usually lower voices help me.

If I may suggest a French podcast, there used to be history podcast by Jean des Cars "Au coeur de l'histoire" (maybe 5 years ago though). I could listen to him while doing something else and get what he said (I'm native French speaker though). When the speaker changed on the podcast, I remember I had to focus very hard to achieve the same level of understanding.

I had the same phenomenon in English, I used to struggle understanding what the remote team would say on the phone, except one person whose voice what very clear.

I don't know how to describe that other than "I don't hear them with my hears, I hear them with my brain".