A blaring horn, the sounds of running water, or pounding footsteps of your toddler bounding through the house—there are a lot of noises that could disturb your baby’s slumber. That’s why infant sleep machines are marketed as an aid to parents whose noisy household or neighborhood makes an extended sleep more possible.

However, a study published online from the journal Pediatrics found some infant sleep machines may emit sounds that are too loud for a baby’s delicate hearing. Fortunately, there are steps you can take to ensure your baby sleeps peacefully without fear of hearing or speech and language development damage.

Researchers from the University of Toronto and the Hospital for Sick Children in Toronto performed the study. The team measured the decibel levels of 14 infant sleep machines. These sleep machines are traditionally used to emit white noise or calming sounds, such as a lullaby. The recommended decibel levels are not to exceed 50 A-weighted decibels. A-weighted decibels are decibels adjusted to the relative abilities of the human ear. The levels were measured when the sound machine was 30, 100 and 200 centimeters from the machine measuring decibel levels.

The researchers found all machines exceeded the 50 A-weighted decibel threshold at 30 cm, and three of the machines exceeded 85 A-weighted decibels at the 30-centimeter mark. If a baby was exposed to these levels for eight hours or more, hearing damage could occur. One machine even achieved a maximum A-weighted decibel range of 92.9 dBa.

In the conclusions portion of the study, researchers did not recommend parents throw out an infant sleep machine, but instead use it more carefully. Major recommendations included:

  • Limit the amount of time the infant sleep machine is used. If possible, purchase a machine that has a shut-off timer.
  • Never putting the infant sleep machine in the baby’s actual crib or attached to a crib rail.
  • Placing the infant sleep machine as far away from the crib as possible.
  • Set the infant sleep machine on a low volume.

If desired, you can purchase apps on your smartphone that give you an estimate of how loud a particular machine or noise is. Sound level meters are also available to purchase at most home electronics and home improvement stores. By keeping the noise as low as possible while still lulling your baby to sleep, you can protect his or her hearing.


  • A study published in Pediatrics found many infant sleep machines played at levels that were too loud for baby’s sensitive ears.
  • Infant sleep machines should not exceed 50 A-weighted decibels and should play for a minimum amount of time.
  • Researchers recommend placing the infant sound machine as far as possible from the infant’s crib.

Last reviewed by Sara Connolly, MD. Review Date: March 2020


  1. American Academy of Pediatrics. Can Infant Sleep Machines Be Hazardous to Babies’ Ears?
  2. Hugh, Sarah C. and N. Wolter, E. Propst, K. Gordon, S. Cushing and B. Papsin. Infant Sleep Machines and Hazardous Sound Pressure Levels. (2013, March 3). Pediatrics. 1-5.


  1. Both of my girls love their sleep machines! My 3 year old can’t sleep without it. They are addicting!


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