Developed for use in impoverished countries like Uganda, the app has now come back home to Canada where its creators realize it would save Western health-care systems both time and money.
"It's cheap, accurate, validated and easy to use," says Dr. Matthew Bromwich, an ENT surgeon at the Children's Hospital of Eastern Ontario in Ottawa who oversaw the development of the app.
Called ShoeBox, the app allows users to perform a hearing test with nothing more than an iPad. It was initially developed for CanHEAR Uganda, a long-running, mostly Canadian program to screen Ugandan children for hearing loss.
But even in Canada screening children for hearing loss is difficult and expensive. The bulky machines used in hospitals cost up to $35,000. Compare that to an iPad that costs roughly $400 and fits in a backpack.
Dr. Bromwich first realized he had a problem when he started making twice a year trips to Uganda to screen children for hearing loss.
Before the trip he and his team would try to raise money for testing equipment that they would then leave behind for the local clinics to use.
But with each return trip he realized that the equipment would often end up broken and piled in a corner of the room.
Even the equipment that was still working would often go unused because there simply weren't enough trained personnel.
Bromwich realized the equipment he was bringing with him was expensive, bulky, complicated to use, hard to maintain and prone to breaking down.
So his research team at CHEO came up with the iPad app, in the process winning a 2014 Research Canada award for mobile health innovation.
The next time he went to Uganda, "we just took 10 iPads and screened 800 kids," Bromwich says. Unlike standard audiometry equipment, the iPads were considerably cheaper and much easier to use.
The app itself "takes five minutes to learn for people comfortable with the iPad," Bromwich says. It's also much quicker.
With the iPad app a hearing test can be performed in about five minutes whereas it would take up to 15 minutes with the conventional machine.
Like a game
The other bonus is that the app is formulated as a game, which makes it particularly attractive to kids.
Rather than sitting at a machine and raising their hands when they hear a tone, as with traditional hearing tests, kids have to sort brightly coloured animals and objects based on whether they make a noise.
"They just play with the iPad," says Bromwich.
After using the app in Uganda, he and his team realized the app had applications and benefits here in Canada.
Instead of flying children down from Iqaluit for hearing tests, which typically costs the government $7,500 in transportation and housing, they could send people up there with an app that requires little special training to use.
By using the app to screen children for hearing loss, only the children who have a problem need to be sent down to Ottawa for further testing and treatment.
Bromwich calls it "intelligent triage." It has spared Iqaluit families an unnecessary multi-day trip to Ottawa and eased an already overtaxed health system.
"You don't want to send kids with normal hearting to get tests," he says. "If you send everyone down, it overwhelms the system."
Schools the next frontier
The app then ended up having yet another use much closer to home.
David Chan, a medical student at the University of Ottawa, was working with Bromwich analyzing data from the Iqaluit project when he had an Aha! moment.
"Honestly, I was just going to be bed and right before I fell asleep I was like, 'Oh my God!' This app would be perfect just to bring it to screen in schools," Chan says.
He brought the idea to Bromwich and he loved it too.
Both Canadian and American medical guidelines say that all children in Canada should be screened for hearing loss, but because of budget constraints, few ever are.
"People just don't have access," Chan says. That prompted him to launch iHEAR, a program of 27 medical student volunteers who took the app into eight Ottawa elementary schools in February 2015 to screen children for hearing loss.
Since February, they found three cases of hearing loss that would otherwise have gone undiagnosed.
The key to treating hearing loss is to diagnose it early; otherwise it can cause learning difficulties, language problems and behavioural issues later in life.
Since access to formal hearing testing is so difficult, most children have their hearing tested manually.
A doctor will rub her fingers next to a child's ear and ask if the youngster heard the sound.
"It's 2015," Chan says, "We can come up with a better solution. That's the purpose of the project."
As Bromwich puts it, it's a perfect example of reverse engineering. "A Third World solution is being put to use for a first world problem."
Christopher Labos is a cardiologist and epidemiologist at the McGill University Health Centre. He is currently a fellow in global journalism at the Munk School of Global Affairs at the University of Toronto.