White noise machines could be hurting your baby's hearing.

Researchers tested 14 of the most popular machines and found three of them operating from one foot away and left on all night produced such intense sound levels they would exceed allowable noise limits for adults.

It should be noted these machines were turned all the way up. However, even at lower limits it could be more dangerous for babies because their hearing is much more sensitive than in adults.

The study's conclusion recommends that parents keep the machines down as low as possible, as far from the baby as possible, and for as short a time as possible. Or maybe not use them at all.

--Rob Archer