My wife puts on RyconRoleplays or ChristopherOdd in the background sometimes when she’s having trouble sleeping. Rycon might have the voice you’re looking for; Odd’s narration depends on the game he’s playing, he likes to set the mood in more atmospheric games, and he reads out every bit of lore.
Clarkesworld is a sci-fi magazine with free audio versions on their site, plus on Spotify as a podcast. I’d recommend “The very Pulse of the Machine” personally as an intro. It was adapted into a great episode of “Love, Death + Robots”.