Listening to pink noise, commonly used in sound machines and apps marketed as sleep aids, was associated with a decrease in restorative REM sleep and worse overall sleep recovery than wearing earplugs ...

Sound machines may not be the sleep saviors many believe. Researchers found that pink noise significantly reduced REM sleep, while simple earplugs did a better job protecting deep, restorative sleep ...

Plenty of people use apps and ambient sound machines to reduce clamor and improve their sleep — but not all noise is created equal. In fact, new research suggests that a particular type could ...