Hand dryers are ubiquitous in public restrooms, but according to research recently published in the Canadian journal Paediatrics & Child Health, the noise they make may be harmful to children's ears.
And the study's author can speak from personal experience.
"Sometimes after using hand dryers my ears would start ringing," 13-year-old Nora Keegan from Calgary, Canada, tells NPR. "I also noticed that children would not want to use hand dryers, and they'd be covering their ears."
So when she was 9, Nora decided to test the volume of hand dryers and find out if they were detrimental to children's hearing. Nora's research confirming her hypothesis was published in June.
"Hand dryers are actually really, really loud, and especially at children's heights since they're close to where the air comes out," says Nora, noting that children's ears are more sensitive.
For the study, which was conducted between 2015 and 2017, she visited more than 40 public washrooms in Alberta, Canada. She used a professional decibel meter to measure sound levels of hand dryers from various heights and distances.
The young scientist then presented her research at a Calgary Youth Science Fair earlier this year.
She discovered that Xlerator hand dryers and two types of Dyson Airblade hand dryers posed the greatest threats to children's hearing. These types all exceed 100 decibels — a volume that can lead to "learning disabilities, attention difficulties, and ruptured ear drums," according to the study.
"My loudest measurement was 121 decibels from a Dyson Airblade model," she says. "And this is not good because Health Canada doesn't allow toys for children to be sold over 100 decibels, as they know that they can damage children's hearing."
In response to these results, Dyson confirmed to NPR in an email that an acoustics engineer would be meeting with Nora to discuss her research. Excel Dryer, the company that sells Xlerator hand dryers, did not respond to a request for comment before this story was published.
Congratulations to #CYSF2019 @TedRogersFund award winner, Nora Keegan, who’s ongoing research into the loudness of automated hand dryers in public places was published in the Journal of Paediatrics & Child Health! #makemorepossible pic.twitter.com/gKUcaqCi5c— YYC Science Fair (@ScienceFairCYSF) June 19, 2019
"While some other units operated at low sound levels, many units were louder at children's ear heights than at adult ear heights," the study concludes.
Nora hopes her findings will spark more research into the issue and eventually lead Canada to regulate noise levels for hand dryers. But for now, she's taking a break and spending her summer like many 13-year-olds — at camp.
Update July 12: Excel Dryer, which owns Xlerator hand dryers, provided this statement after this story was originally published:
At Excel Dryer, we are committed to our customers. User experience is very important to us, which is why all our high-speed, energy-efficient models come with adjustable sound and speed controls as a standard feature. This allows facilities the ability to choose the best settings for their restroom environments.
Ashley Westerman produced the broadcast version of this story.
RACHEL MARTIN, HOST:
It is a routine we all know well.
(SOUNDBITE OF TOILET FLUSHING, SINK RUNNING, HAND DRYER BLOWING)
MARTIN: Flush, wash, dry.
STEVE INSKEEP, HOST:
But did you know that many hand dryers are actually harmful to children's hearing? That's according to a study published by the Canadian journal Paediatrics & Child Health.
NORA KEEGAN: Hand dryers are actually really, really loud and especially at children's height, since they're closer to where the air comes out. And also, children's ears are more sensitive.
MARTIN: The study's author is 13-year-old Nora Keegan of Calgary. She has been studying this issue since she was 9.
NORA: Sometimes after using hand dryers, my ears would start ringing. And I also noticed that children would not want to use hand dryers. And they'd be, like, covering their ears. So I wondered, maybe we are just thinking that children are too sensitive. But maybe actually they are too loud, so I decided to test it.
MARTIN: Keegan measured over 40 hand dryers in public washrooms.
INSKEEP: And found that many dryers run louder than the manufacturers claim and often at noise levels that are not safe for children.
NORA: So at around 110 decibels, but my loudest measurement was 121 decibels from the Dyson Airblade model. And this is not good because, like, Health Canada doesn't allow toys for children to be sold over a hundred decibels, as they know that they can damage children's hearing.
INSKEEP: Wow. This is amazing. Now, she hopes that her sound science will move Canada to regulate hand dryers. But as for her future in this specific research...
NORA: At the moment, I'm not sure if I'm going to continue this project or not. But I want to be a scientist when I grow up.
MARTIN: Indeed. Keegan says Dyson has reached out to her. But she hasn't had a chance to talk with them yet because, like so many of her peers, she is away at summer camp. Transcript provided by NPR, Copyright NPR.