When Nora Keegan would visit a restroom and use a hand dryer, she often thought it sounded too loud. Sometimes she’d notice other children stuffing their fingers in their ears to quiet the roar of the dryer while exasperated parents looked worried that their child was too sensitive. That’s when Nora, then 9, decided to measure sound coming from the hand dryers for a science fair project.
Nearly four years later, the Canadian journal Paediatrics & Child Health published a paper she wrote about the findings showing that Nora’s instinct was right.
“Sometimes after using hand dryers my ears would start ringing,” the 13 year old, soon-to-be ninth grader from Calgary, Canada, told TODAY Parents. “I started wondering that maybe (hand dryers) are too loud for our ears.”
Starting when she was in fourth grade, Nora, with the driving assistance of her mother Dr. Susan Bannister, visited public bathrooms around the city to look for dryers. Nora took 20 measurements at each dryer, more than what the manufacturers record for their products.
“They didn’t measure at different heights,” she explained.
Nora measured the sound of the hand dryer at the average height of a 3 year old’s ear canals, the average height of an adult woman’s ear canal, the average height of an adult man’s ear canal and standing both 12 inches and 18 inches away from the dryer. While the manufacturers test the sound 18 inches from the wall, Nora suspected that children stood closer to the dryer so they'd be closer to the noise. She also tested how the hand dryer sounded with hands in the airflow and without hands in the airflow, in part, because of a mishap during testing.
“My hand accidentally went into the airflow so the decibels went up,” she said.
Finding hand dryers was sometimes difficult. They’d arrive at a public bathroom to find that it had paper towels. That is until people started telling Nora where the loud dryers were, such as the science center, which had dryers that annoyed almost every child. Spending time in the bathrooms wearing noise cancelling headphones and holding a measuring stick often led to interesting interactions.
“We did these informal focus groups in the bathroom that was not planned as part of her research. It was chit chat because it was all sort of awkward,” Bannister, 49, a pediatrician in Calgary, told TODAY Parents.
After Nora explained her study, she overwhelmingly heard she had a good idea.
“It is fascinating that she seems to have hit a nerve with people. When she was doing this research I said to her, ‘You are onto something. People hate these things,’” Bannister said. “For certain groups of people this is even more disturbing than for others. This is interesting.”
Nora agrees. She was glad her hunch paid off.
“I thought that it was really cool that this thought I had turned out to be an actual thing,” she said.
She said the Xlerator hand dryer, Dyson Airblade and Dyson Air Blade V are the loudest, operating at about 110 decibels. According to the Centers for Disease Control and Prevention, noise at 85 decibels can cause hearing damage if people are exposed to the sound for a prolonged period of time. Sound that is 120 decibels, just 10 decibels higher than hand dryers, can immediate hurt ears. That's why Nora hopes that her research encourages companies to rethink the dryers.
“I hope it has an influence for manufacturers to change their testing methods because the hand dryers were way louder than they claimed. I don’t think they measured them in real life conditions,” she said. “It will save ears.”