Hotel rooms
Hotel rooms are often smaller than your nursery, so distance is limited. Place the machine as far from the crib or pack-n-play as possible — even on the bathroom counter with the door cracked can work if the room is tiny. Hotels have unpredictable noise: ice machines, elevators, hallway conversations, thin walls. White noise masks all of it.
Grandparents' house
The main challenge here is unfamiliar sounds: different HVAC, creaky floors, pets, a ticking clock. White noise provides a familiar sound blanket over all of it. Place the machine the same way you would at home — across the room, below 50 dB. If grandparents are worried about the noise bothering them, reassure them: at 50 dB from 7 feet, they won't hear it outside the room.
Vacation rentals / Airbnbs
These are the most unpredictable. You don't know the noise environment until you arrive. Street noise, thin windows, shared walls, unfamiliar appliances — all reasons to bring a machine. Test the room acoustics when you arrive: run the machine and check with a decibel app. Adjust placement based on the room layout.
Car naps
The car is already noisy (road noise is about 60–70 dB), so a sound machine isn't usually necessary during drives. If your baby naps well in the car, the motion and road noise are doing the job. If you stop and your baby is sleeping, turning on a portable machine on the dashboard can help maintain the sound floor during the quiet pause.
Stroller naps
A small, clip-on sound machine attached to the stroller canopy can help mask street noise and conversation during on-the-go naps. Keep it on the canopy, not near your baby's ears. Volume should be modest — you're supplementing the ambient sound, not drowning it out.
Airplane
The airplane cabin itself runs about 80–85 dB — louder than any sound machine you'd use. Your baby is essentially in a white noise environment already. A sound machine won't add much on a plane. For fussiness during takeoff and landing, nursing, a bottle, or a pacifier to help with ear pressure is more effective.