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.

Source: 13-Year-Old Scientist’s Research Shows Hand Dryers Can Hurt Kids’ Ears : NPR