Hm well I shouldn't say interviewees but one of the subjects of the podcast. So the host will be narrating something and the pre recorded interview is playing at a very low volume in the background and will pop through when a relevant point is made (for dramatic effect) - and then that person continues talking so you're primed to expect something more, but they are quickly faded before the host comes back to talk over them and continue the narration. I just find it so distracting.
But it's actually seemingly common on big, professionally made podcasts like This American Life and this CBC podcast I'm listening to