The alert we've been discussing all morning long. Parents with young children, take note. They'll try just about everything. I know I will to get our kids to sleep but one of the most popular ways may... See More
The alert we've been discussing all morning long. Parents with young children, take note. They'll try just about everything. I know I will to get our kids to sleep but one of the most popular ways may be doing more harm than good. ABC's Mara schiavocampo has the story. ♪ Reporter: Noise machines, touted as the secret to help your baby sleep. Many labeling them nursery must haves but now one study says that regular use of these machines could increase the risk of damage to an infant's hearing. Researchers looked at 14 infant sleep machines and found that at their loudest and placed distances ranking from about 12 to 79 inches, almost all of them exceeded 50 decibels, the recommended limit for a hospital nursery. And three of them exceeded 85 decibels at about 12 inches simulating placement on a crib rail. That's louder than a garbage disposal, blender or vacuum. Carrie Ann has used them for years with her two kids. I wanted it and it just drowned out the house noise, drowned out the backyard noise. The doorbell, everything. Reporter: With our own meter, we tested noise levels in the kids' rooms. 56. Depending on how close we were to the machine, the noise reached -- 72. I probably use it as often. Reporter: Researchers didn't test the effective of these machines on children, but some worry big noise isn't good for little ears. This is a period of rapid development. What to worry about exposure is not just how loud but how long you're exposed to it. Reporter: The juvenile products manufacturer's association told ABC news that it, quote, encourages parents to follow guidance and instructions and that its members, quote, welcome information that may advance the safety and well-being of children." If you're going to use the machine keep the volume low. Move them away from the crib. Don't leave them on all night and use phone apps to monitor decibel levels. Tips to help children and their parents rest easier. For "Good morning America," Mara schiavocampo, ABC news, new York.
This transcript has been automatically generated and may not be 100% accurate.