I’ll listen to most things around my kids except grisly murders! But classic audiobooks are lovely to have on. You could choose childrens classics if you wanted to, as lots of adults enjoy them too, even if they are beyond a four year old level. Even those with more adult themes will tend to go over their heads, and if they don’t you can explain in an age appropriate way. Disclaimer - I’m very relaxed about language and adult subjects, and my DC seem well balanced people so far! But do feel free to vet them as I’m sure I’ve misremembered some parts or might let some swear words in. My DC are varying ages so the smaller ones have always had bigger kids stuff to watch or listen to.
Classic childrens we’ve enjoyed on audiobook - Five Children and It, Heidi, Pollyanna, Black Beauty, Treasure Island, Alice in Wonderland, A Little Princess, Lion Witch and Wardrobe, Northern Lights, The Hobbit, The Secret Garden, Tom’s Midnight Garden, 1,001 nights, Ronia the Robbers Daughter, Earthsea quartet, Roald Dahl
More adult books - Dickens, Austen, Brontes, Gaiman, Pratchett.
More factual and podcast stuff - Something rhymes with purple, 1000 of the worst ideas in history, Into the Blue, Oceans Life under water, BBC Earth podcast, Naturebang, how I built this, herstory, horrible histories!