Can White Noise Wake Up a Baby?

Why White Noise is Effective

• Dr. Harvey Karp, who wrote the book "The Happiest Baby on the Block," says that newborn babies are in what he calls "the fourth trimester." They still do not know they are a separate person from their mother. It is helpful to simulate the womb environment as much as possible for them to ease the transition and comfort them. Playing white noise can simulate the sound of the womb, which can calm babies and encourage them to sleep more. The sound of total silence can actually be quite unnerving for babies, Dr. Karp says.

Other Benefits of White Noise for Sleep

• White noise not only calms babies enough to get them to sleep, but it can also help them to sleep longer, Dr. Karp says. The noise creates a continuous sound, which not only soothes your baby throughout sleep but also blocks out other noises that might wake your baby. The combined effect is that your baby may sleep longer -- up to 1 to 3 hours longer, according to Dr. Karp. He says that the white noise makes babies feel cozy and relaxed and refers to it as an "auditory teddy bear." Dr. Karp says that white noise can also help distract babies from mild hunger and the pain of teething, both of which could wake your baby.

Types of White Noise to Use

• You can use many of the devices in your own home to create white noise that your baby will find soothing. WebMD recommends noises such as a clothes dryer, fan or vacuum. You can also buy a CD of white noise or a machine that creates white noise, such as the sound of static, a mother's heart beat or rain falling. Dr. Karp says that parents need a loud white noise in order to calm crying babies, such as a vacuum cleaner. To promote sleep, the sounds should still be rough but just a bit quieter, such as a hair dryer. Karp says the sound should be as loud as a shower, as milder sounds like those of ocean waves are too quiet to be effective. Karp notes that the sound inside the womb was louder than a vacuum cleaner, and your baby heard that every moment of the day.

How Long to Use It

• If you use white noise just long enough to get your baby to fall asleep, he may wake up once you turn it off. The continuous sound creates a soothing effect for babies. Dr. Karp recommends that parents play white noise whenever their baby is sleeping, whether it is during nap or nighttime sleep. You can play the noise through the duration of the night. Use the white noise for as long as it is helpful for your baby. Dr. Karp says that white noise can be used through your baby's first birthday, if it is helpful.