We do ours at 35% and it’s across the room from the crib
28-30. Probably 8’ away.
We do keep it at 22-23volume and within the reach bedside table :) I love the app to control it!!
Mines right by the door to block the noise from the hallway (prob 8ft away), I usually have it around 25-30%
I have the Hatch Rest + and I turn it on 40-50 a couple feet from the bed. I looked it up and found out hearing damage starts around 85 decibels for babies. If I'm not mistaken, the decibels are in the 50s at that volume. (Downloaded a sound meter)
I put the hatch on volume 11-15 max. Just faint in the bg. It's recommended to be kept at least 7 feet away.