Playing white noise at night to soothe a restless baby can do more harm than good if it disrupts their sleep cycle, the study warns
- Millions have downloaded white noise apps to help combat insomnia
- Soothing noises such as waves or nature sounds are supposed to support sleep
- However, new research suggests that the drug could do more harm than good
Whether it's the hum of a fan or synthetic sounds from a smartphone, parents often turn to what is known as “white noise” to help a restless child fall asleep.
However, a review of 38 different studies found that it can do more harm than good by significantly disrupting the natural sleep cycle.
Apps that produce white noise are popular – the iPhone's Bedtime fan app has over three million downloads, while the Android White Noise Generator has over a million.
Whether it's the hum of a fan or synthetic sounds from a smartphone, parents often turn to what is known as “white noise” to help a restless child fall asleep. However, a review of 38 different studies found that it can do more harm than good if the natural sleep cycle is significantly disrupted.
Mathias Basner, professor of psychiatry at the University of Pennsylvania Medical School in Philadelphia, told The Guardian, “If these apps or devices could only do good, I wouldn't really care.
"But because there can be negative consequences, I would just be careful."
The term "white noise" technically refers to a repetitive hissing sound at various frequencies, but is also used as an abbreviation for calming sounds that drown out background noise.
Professor Christian Cajochen from the Center for Chronobiology at the University of Basel in Switzerland said: "Any acoustic stimulus that is continuous or not can interrupt the sleep process."
Using a fan is the most common option, although modern apps allow a sleepless person to capture calming recordings such as waves or nature sounds.
One theory about its supposed effectiveness is that it is a self-fulfilling prophecy: the sound of a fan helps you sleep because you turn it on before you go to bed.
Dr. Basner fears that the human hearing system will not turn off overnight – although this still has to be put to the test.
"Whenever we are exposed to sounds and noises, the inner ear translates this into nerve signals that are then interpreted by the brain," he said.
'It is an active process that creates metabolites, some of which have been shown to be harmful to the inner ear.
"You probably want a period when the auditory system can relax, rejuvenate, and prepare for the next wake-up period."