This sleeper comes with a built - in gentle white noise sound machine and soft light that can help your baby feel more comfortable and sleep better, too. (abckidsinc.com)
You can also replace the sound card to get a new set of white noise sounds. (whitenoisemagic.com)
A simple white noise sound generator in the bedroom helps to keep your mind quiet in the middle of the night and masks disruptive outside noise. (mindbodygreen.com)