I’ve put tape over the speaker so it’s much quieter x
I used standard settings for both my babies and their hearing seems fine!
My cousin used it for her twins who are now 3 and has no issues. We've had no issues too but our baby is only 1.
My husband disabled the sound machine and we use a Hatch which we can have across the room.
My son used the snoo with the white noise on high (at least until he fell asleep) and I haven’t noticed any issues with his hearing at all. Doctor hasn’t either. It might be worth asking the pediatrician about, though. I wasn’t aware it was that loud (just never measured it.) I think higher dB become more concerning the longer they’re exposed to it