Scientists may have the key to treating tinnitus: Retrain the brain
An innovative treatment offers hope to the millions of people who hear sounds that others don’t. Here’s how it works.
Millions of people have tinnitus, a bothersome condition that causes ringing or other noises in their ears. There is no known cure. But a new treatment is reducing symptoms in many patients.
To understand how it works, let’s start with how healthy ears hear a note on the piano.
The technology is being hailed by some audiologists as a “game changer” for treating tinnitus, which experts estimate affects roughly 10 percent of U.S. adults.
“This offers something very different than anything we’ve ever offered in the tinnitus world,” said Gail Whitelaw, an audiologist and clinical professor at the Department of Speech and Hearing Science at Ohio State University.
Scientists have developed several devices that use the technique of bimodal neuromodulation. Two of them are available in the United States: Lenire, which is shown above, and Duo, a device that stimulates the wrist. A third, which delivers electrical pulses to the neck or jaw, has been developed by researchers at the University of Michigan but isn’t yet on the market.
Studies published in peer-reviewed journals showed the devices reduced the severity of people’s tinnitus symptoms, based on responses to validated questionnaires designed to measure the condition’s severity.
But there are limitations. The studies were relatively small and conducted by the companies and researchers behind the devices. More long-term, independent research is needed. In addition, the studies on Duo and Lenire devices didn’t include a placebo-controlled group.
A study on the device developed at the University of Michigan compared it with a placebo, but Susan Shore, the researcher behind the treatment, acknowledged that patients could have been so excited about receiving any type of treatment that a placebo effect was possible.
James Henry, a clinical researcher in the Portland, Ore., area who has studied tinnitus for over 30 years, called the research “compelling,” although he cautioned that explanations for why these treatments seem to work are still theoretical.
“We cannot rule out the placebo effect behind any of these methods,” he said.
But for patients who have found relief from the treatments, bimodal neuromodulation is offering hope for something they’ve long yearned for: a sense of peace.
Discoveries in tinnitus and the brain
Audiologists don’t know what causes tinnitus in most cases. The condition may be temporary and go away on its own. For others, it can be severe and chronic.
Some patients describe their tinnitus as sounding like ringing, but it can also sound like buzzing, static, sirens or even clicking. Many people can make the sound change in loudness or pitch by moving their body. This occurs because the sensory system relating to touch, called the somatosensory system, is connected with the auditory system, said Shore, a professor emerita at the University of Michigan.
Shore began researching the auditory system over two decades ago because she wanted to learn how it interacts with other sensory inputs. She focused on an area of the brain called the dorsal cochlear nucleus, where input from somatosensory nerves from the face and neck interact with input from the auditory nerve.
Because this area is deep in the brain, it is difficult to study through MRI exams and other imaging tools. So Shore’s team studied guinea pigs with tinnitus. When they inserted probes inside the brains of the guinea pigs, the researchers found that the cells in the dorsal cochlear nucleus fired much more than usual.
These cells “trick the rest of the brain into thinking that there’s a sound there when there isn’t a sound there,” Shore said. “They generate the tinnitus.”
Based on her research, she designed a tinnitus treatment that also uses bimodal neuromodulation.
When Shore tested her treatment in the guinea pigs, she found that it reduced the cell activity in the dorsal cochlear nucleus thought to cause tinnitus. In human trials, many people reported a reduction in tinnitus symptoms.
Breakthroughs in treating tinnitus
Lenire’s approach to bimodal neuromodulation is different: This device aims to increase the brain’s sensitivity to other sounds — besides the tinnitus. It stimulates the tongue, rather than the neck or jaw.
Ross O’Neill, who co-invented the Lenire device, said he focused on the tongue because a very low amount of electricity is needed to stimulate it. Nerves in the tongue are also thought to be associated with increased neuroplasticity — the brain’s ability to change — and believed to activate parts of the brain associated with attention, said Hubert Lim, the chief scientific officer of Neuromod Devices, the Dublin-based company that created Lenire, and a biomedical engineering professor at the University of Minnesota.
Lim and Shore said the advancements in bimodal neuromodulation could have implications for the treatment of other conditions influenced by brain activity, such as chronic pain or post-traumatic stress disorder. Lim has started investigating the potential of this technique to treat chronic pain.
David Eagleman, a neuroscientist and professor at Stanford University, thinks the reason bimodal neuromodulation seems to work is that it can help teach the brain what sounds are real.
Eagleman was developing a vibrating wristband as a treatment for hearing loss when he came across Shore’s research in 2020. He decided to test whether stimulating the wrist — as opposed to the neck and jaw like in Shore’s device — could reduce the symptoms of tinnitus.
The device, called Duo and distributed by Eagleman’s Neosensory company, uses an app that plays tones at various pitches and targets the somatosensory system through the vibrating wristband.
In a study of 45 participants, the company found that those who heard audio paired with vibrations on the wrist had a clinically significant reduction in their tinnitus severity scores, whereas those who only heard audio tones did not.
“Every time you hear an external sound, you get verification,” Eagleman said. “As a result, it teaches the brain, ‘Hey, this other sound is fake,’ and it drives the tinnitus down.”
Some patients are finally finding peace
Bojan Radojevic’s tinnitus sounded like high-pitched ringing — as loud as a scream. The 56-year old in Chandler, Ariz., started experiencing tinnitus in March 2021 without any clear explanations.
The noise made it hard for Radojevic to sleep, work and eat. In a matter of months, he lost around 25 pounds. He cycled through standard and experimental treatments. He tried white-noise machines to cover up the constant ringing. He wore hearing aids that played sounds like running water in his ears. He got counseling to help him get used to the sound. He even tried ketamine therapy.
Nothing worked.
Standard treatments didn’t work for Susan Rivas, 59, of Aurora, Colo., either. Her tinnitus started after she got sick with a bad flu in 2002 and got worse over time. For more than two decades, she has heard sounds like ringing, chirping and different pitched notes in her ear. Eventually, she tried experimental treatments like hypnosis and took herbal supplements — all to no avail.
“You get to the point where you’d give up your right arm to get rid of the noise,” she said.
Radojevic and Rivas started using bimodal neuromodulation treatments through Lenire last year. They used the device twice a day for 30 minutes over the course of 12 weeks. Both noticed improvements in their sleep after just a day and continue to use the devices regularly.
Radojevic said his tinnitus is “almost nonexistent.” Rivas said she can still hear the tinnitus, but it doesn’t bother her anymore.
“It’s been sort of magical. It’s actually been life-changing,” she said.
Emily E. McMahan, an audiologist based in Anchorage who specializes in tinnitus, has treated over 200 patients with Lenire. Some have found their tinnitus is less noticeable or not as bothersome, but others haven’t seen an improvement.
“Lenire is a tool, but it can’t be the only portion of treatment,” McMahan said. “You have to come from a whole-body approach and taking care of that entire person.”
She doesn’t plan to stop recommending other treatments like cognitive behavioral therapy and hearing aids, but she intends to use Lenire in conjunction with these other treatments.
How to get treated
Both Duo and Lenire can be used in somatic tinnitus — when the tinnitus sound can be influenced by body movement and manipulation — and non-somatic tinnitus. The devices are not widely covered by insurance. For that reason, Henry, the Oregon researcher, recommends that tinnitus patients work with their audiologists to try free or inexpensive tinnitus treatments first.
Here’s what else patients need to know about trying the bimodal neuromodulation treatments.
Lenire: The device, which has FDA approval for treating tinnitus, is only offered through audiologists. Cost can vary, but it ranges from about $3,000 to over $4,000. There are waiting lists to try Lenire, in part because there are so many people who suffer from tinnitus and because there are a limited number of audiologists offering it.
Duo: This treatment is sold directly to customers for $249 a month as a “wellness device.” It is seeking approval from the Food and Drug Administration to be sold as a medical device. After four months of payments, you get to keep the wristband and can use the device afterward at no further cost. The app is always free. The company recommends using the device for at least 10 minutes every day for at least eight weeks.
Shore’s device: A private company, Auricle, is trying to get FDA approval for Shore’s device, which targets those with somatic tinnitus. The company has not released a timeline or name for the device. Auricle plans to sell it through audiologists, who would be able to program the sound to match each patient’s tinnitus and help determine the best placement for the electrodes.