En español | Although hearing loss is a very common sensory loss — affecting one-third of all American adults between the ages of 65 and 74 and nearly half of those older than 75 — solutions to hearing problems have been slow to materialize. Until recently, hearing aids only made things louder, not necessarily clearer. And scientists have yet to discover a way to repair damage to the inner ear.
Now, though, thanks to such advances in technology and medicine as artificial intelligence and gene therapy, hearing research is producing significant innovations. Here are some of them, in various stages of development.
1. Eyeglasses that turn speech into subtitles
The big idea: You'll be able to read what people are saying.
How it might work: An app on your smartphone would listen to a conversation and transcribe the speech into sentences in real time. The text would be delivered instantaneously to your enhanced eyeglasses (which would create subtitles, in addition to correcting your eyesight!) using augmented reality (technology that superimposes information on the world we see). The result: It would be like watching TV with subtitles, except without a screen.
Why it's exciting: Automatic speech-to-text programs have proliferated in recent years. Live computer-generated captions are now available on most videoconferencing platforms, and smartphone apps can generate real-time transcriptions for in-person conversations. The problem: Users must be in front of a computer or looking at a phone, which detracts from full social engagement, says Raja Kushalnagar, an information technology professor at Gallaudet University who studies speech-to-text technology for people with hearing loss. Now companies are making subtitles more natural by using “smart glasses” technology, which can project text to a user's field of vision in a comfortable, nonintrusive way. Kushalnagar, who is deaf, recently tested out a prototype. “I was able to walk on the trail with my son and hold a conversation with him easily, which was harder with the phone app,” he says. “I could also cut vegetables and cook as I listened to him talk about his day."
Who might benefit: While subtitled conversation could solve a problem for people with hearing loss, these “smart” glasses with subtitles could find other users, such as for non-native speakers, who might find it easier to read a new language than listen to it. Also, subtitling software could be combined with real-time language translation apps, which would make foreign travel a breeze.
When we might see it: Within a few years. In 2019, Vuzix, a tech company, released high-end smart glasses that work with transcription software by Zoi Meet. And Google Research is testing its own experimental lightweight eyeglasses with subtitles designed for all-day use. Kushalnagar estimates that affordable, comfortable eyewear integrated with automatic captions will be on the market within two or three years.
2. An app that lets you hear someone in a crowded room
The big idea: You can isolate one person's speech in a noisy environment, addressing what scientists call the “cocktail party problem.”
How it might work: An app would “listen” to the soundscape surrounding you and separate out different streams of sound, including voices, clattering dishes, ambient music and other background noise. Then it would isolate the sound you want to hear based on the direction you're facing — and reduce everything else. The “de-noised,” cleaned-up sound would then be delivered straight to your ear through your hearing aid, cochlear implant or earbuds.
Why it's exciting: The cocktail party problem is the “number one complaint by hearing aid users or people with hearing loss in general,” says Fan-Gang Zeng, a professor of otolaryngology at the University of California Irvine who studies hearing technology. Hearing aids and cochlear implants may help in one-on-one situations, but they perform best when there's a single voice to focus on. Artificial intelligence could not only aid but supercharge the listening experience of hearing-impaired people so that it's “better than normal,” Zeng says. For example, a team at Ohio State University recently developed a powerful AI program that can take the audio of two competing speakers in an echo-y room and edit out one voice, leaving just the target voice. In one test of the program, older adults with hearing aids went from being able to understand less than 10 percent of a conversation to understanding more than 80 percent — which actually topped their younger, normal-hearing counterparts, who caught less than 70 percent with their own ears.
Who might benefit: Anyone — including those with normal hearing — who has trouble hearing in crowds or other noisy situations. Zeng says that the line between hearing aids and earbuds is already starting to blur, as off-the-shelf, in-ear headphones continue to add more sophisticated noise-canceling, speech-enhancing capabilities. “De-noising algorithms will lead to use in not only hearing aids and cochlear implants, but also earbuds and ‘hearables’ that will enhance normal hearing and facilitate conversations in noise,” he says.
When we might see it: Zeng estimates powerful de-noising programs will be available on hearing technology within five years.
3. Drug therapy that regrows cells that help your hearing
The big idea: Your body will repair damage to your inner ear — in much the same way that salamanders regrow a tail.
How it might work: A drug delivered into your inner ear would turn on chemical switches to regrow the cells responsible for hearing — and most hearing loss. People born with hearing loss or those who lose hearing later in life would get a few injections to restore some or all of their hearing.
Why it's exciting: In normal inner ears, these crucial hair cells — which are long and flexible and look like tiny fields of grass — react dynamically when sound vibrations arrive from the outer ear: they start to “dance.” The dancing movement of the hair cells is what lets sound travel up the auditory nerve to the brain. We're born with about 15,000 of these delicate cells in each ear, and once damaged, they are gone for good — in humans, at least. In the 1980s, researchers made an interesting discovery, says Lawrence Lustig, M.D., an otolaryngologist (that is, ENT doctor) at Columbia University Medical Center in New York City. They found that birds can regrow their damaged hair cells after trauma; fish, reptiles and amphibians can repair their hair cells, too. Because of this ability, these animals never permanently become deaf. Hearing researchers are trying to replicate this process in humans.
Who might benefit: Hair cell regeneration would be a game-changer for anyone who has lost hearing as a result of missing or damaged hair cells. Babies born deaf from specific genetic conditions would likely be an early group to receive this therapy. People who have begun to lose their hearing later in life — soldiers and workers who have worked in extreme noise, for example, or simply those whose inner ear has suffered from the wear and tear of aging — could also be good candidates.
When we might see it: Not real soon. A few hair cell regrowth therapies using different methods are currently in human clinical trials, including ones from Novartis, Eli Lilly, Frequency Therapeutics and Pipeline Therapeutics, but most are still being tested in the lab. Lustig is confident that researchers will find ways to treat hearing loss with medicine.
Editor’s Note: This story was corrected on Aug. 5 to say that drug therapy regrows cells that help hearing.
Regina Nuzzo writes about science, health and medicine. Her work has appeared in Reader’s Digest, Prevention, Scientific American, the Los Angeles Times, and The New York Times, among others. She is a professor of mathematics at Gallaudet University in Washington, D.C.