It may help, and it also helps with the fourth trimester theory.
Jenna says: “My son sleeps in my room, so he hears me breathing all night. I think it’s really soothing, and I’ve heard that it helps protect against SIDS, as hearing our breath helps the baby regulate his own breathing.
For the first part of the evening, before I’ve gone to bed myself, I use an app called Zen Breath Meditation. It basically sounds like someone calmly breathing. It makes it sound like someone is still in the room. I leave my phone in the room with my baby, on flight mode, with the breathing noise. He is reassured by it if he stirs a little, and it has stopped his frequent wakings.
Also, I breathe quite audibly and calmly as I settle him and sneak off, rather than aiming for total ninja silence!”