Once your tot is using white noise to go (and stay) asleep, will they have it forever? That depends on you, according to Dr. Karp.
"That's your choice at least for the first year. Parents always ask, don't they become addicted and stuck to it? And the answer is No. 1, they're addicted to it when they're born, so to go from having it 24/7 to none is way too abrupt for a baby. No. 2, you can wean it. The beauty of white noise, and swaddling for that matter, is you can wean it in steps. If you want to wean the sound, you just gradually lower the sound over a week or two and it's gone. Sleeping with your baby or nursing your baby to sleep, it's all or none. It's much harder to wean them off of that. Sleep cues are not a bad thing."