Cochlear implants—small, surgically implanted electronic devices that enable someone who is deaf or severely hard of hearing to hear—are used by more the 325,000 people worldwide. While the devices don't restore normal hearing, they provide a useful representation of sounds, making it possible to understand speech. Many people, however, face challenges learning to use cochlear implants, largely because auditory training opportunities are limited.
Three undergraduate students from the Department of Biomedical Engineering at Johns Hopkins University have come up with an iPad app called Speech Banana that expands access to auditory training, giving deaf adults with cochlear implants the ability to practice on their own. Their work is overseen by Tilak Ratnanather, an associate professor at Biomedical Engineering who was born deaf but learned to communicate using hearing aids. Ratnanather received a cochlear implant in 2012, and he knows firsthand the trials of learning to use it.
"With a cochlear implant, it is not the same as normal hearing. It's electrical hearing. … You have to train the brain to interpret the signals," Ratnanather says.
Unfortunately, he says, many adults with cochlear implants don't have access to auditory training, or their insurance companies don't provide coverage for it.
"I'm fortunate because I work at Johns Hopkins," he says. "I go to the clinic once a week for an hour, and I've been doing that for two years. Some people only get one or two in-person training sessions a year."
That's where Speech Banana comes in. The app—named for the region on an audiogram where all the phonemes of spoken languages fall—doesn't replace in-person auditory training. "But we want to supplement it," says Margo Heston, a rising-senior biomedical engineering student.
The student team, which also includes BME rising-senior Rohit Bhattacharya and BME rising-junior Joanne Song, has a version of their app in beta testing with about 50 adults worldwide. They plan to make an Engliash-language version available to the public later this year, and they hope to secure funds to translate it into other languages.
Heston says the team has put in hundreds of hours on the project so far, and while they received research credit last summer, they now consider it a personal calling.
"This has real tangible potential to improve a person's functionality," she says.
This article was originally published in the Summer 2014 issue of JHU Engineering magazine.