White noise from a Bluetooth speaker made a huge difference for our daughter when it came to sleeping. It’s not bulletproof but it worked by keeping her quiet and sleeping for relatively long periods of time. Now we never use it and she sleeps all through the night.
Discussion
Great, I'll put that on the list of things to do if he can't sleep. So far he's been doing great - gets food (demands more than what tables say...), falls asleep right after and can get safely swaddled. Fingers crossed that this stays...