Georgia Tech professor is studying sound therapy for Alzheimer’s and here’s what her research reveals
A small MIT clinical study published in 2025 is drawing fresh attention to sound therapy specifically, a light-and-sound treatment being tested as a potential way to slow cognitive decline in people with Alzheimer’s disease. The early-stage research followed five patients with mild Alzheimer’s for two years and found the daily at-home therapy was safe, feasible and, in some participants, appeared to slow the disease’s progression.
The findings are preliminary, and the sample is small. But for families navigating a diagnosis with few good treatment options, the study offers a rare piece of encouraging news and a look at how researchers are rethinking what a therapy for this disease could even look like.
What the MIT Study Found About 40 Hz Sound Therapy
The MIT pilot tested a noninvasive treatment called GENUS, short for gamma entrainment using sensory stimuli. Participants used a device at home that delivered flickering light and clicking sound at 40 hertz for one hour a day. Over two years, no adverse events were reported. Three of the five participants all women with late-onset Alzheimer’s showed meaningfully less decline than comparable patients pulled from major national databases.
“The results show that for the three participants with late-onset Alzheimer’s disease, several measures of cognition remained significantly higher than comparable Alzheimer’s patients in national databases. Moreover, in the two late-onset volunteers who donated plasma samples, levels of Alzheimer’s biomarker tau proteins were significantly decreased,” MIT reported.
The two other participants both men with early-onset forms of the disease did not show significant benefits after two years. The researchers were careful about what the data can and cannot show.
“This pilot study assessed the long-term effects of daily 40 Hz multimodal GENUS in patients with mild AD,” the authors wrote in Alzheimer’s & Dementia The Journal of the Alzheimer’s Association. “We found that daily 40 Hz audiovisual stimulation over two years is safe, feasible, and may slow cognitive decline and biomarker progression, especially in late-onset AD patients.”
The three women with late-onset Alzheimer’s retained strong EEG entrainment and showed less decline on the Mini-Mental State Examination, Clinical Dementia Rating and Functional Assessment Scale compared with matched controls from three national research databases. Plasma samples were available for only two participants, both with late-onset disease. Those two showed pTau217 reductions of 47% and 19% a promising signal for a biomarker closely tied to Alzheimer’s progression.
How Flickering Light and Sound Therapy Is Being Studied Elsewhere
Sound therapy for Alzheimer’s isn’t limited to the MIT team. Annabelle Singer, an associate professor and biomedical engineer at Georgia Institute of Technology and Emory University, is running her own research using light and sound to probe what goes wrong in the brains of Alzheimer’s patients. Her setup uses goggles that resemble ski goggles paired with headphones that deliver rapid clicks and beeps.
“We are taking a really different approach to Alzheimer’s,” Singer said, per CNN. “We’ve determined how neural activity that is essential for memory fails in Alzheimer’s disease. We’re then using that information to develop brain stimulation that could improve brain health.”
The goggles flicker at a rate about five times faster than the average strobe light. Preclinical work and a feasibility study found that flickering light and sound at 40 Hz for an hour a day had potential to slow cognitive decline and volume loss in parts of the brain critical for memory.
“Both those things are really promising,” Singer said. “We don’t know that we can reverse the memory impairment that’s already there. Instead, what we’re going for is to slow the continuing decline.”
Her framing helps explain why this line of research is different from the drug development that has dominated Alzheimer’s treatment for decades. “The majority of research on Alzheimer’s disease focuses on the molecular scale how proteins accumulate or go wrong,” she said. “We’re asking, how do neurons behave electrically to generate memory and how do those patterns change in Alzheimer’s patients?”
Earlier Clinical Trials on 40 Hz Sensory Stimulation
The MIT pilot builds on earlier trials that also pointed to safety and some encouraging signals. According to the Alzheimer’s Research Association, two early-stage clinical studies of 40 Hz sensory stimulation for Alzheimer’s found the therapy was well-tolerated, had no notable adverse effects and was associated with neurological and behavioral advantages in a small group of patients.
A phase 1 trial included 43 participants 16 with early-stage Alzheimer’s and two people with epilepsy who were about to undergo brain surgery. Researchers used scalp electrodes to track activity in the frontal and occipital lobes before, during and after the sensory stimulation. In the epilepsy patients, activity in deeper brain regions was measured during surgery. Gamma wave strength appeared to rise across brain areas during treatment, and synchronization increased in the frontal and occipital lobes. Sleepiness was the most commonly reported side effect. No serious adverse events were noted.
A phase 2a trial sent GENUS devices home with 15 people who had early-stage Alzheimer’s. Each unit included a light panel connected to a speaker along with video cameras to monitor use. Participants were randomly split into two groups. Eight received 40 Hz light and sound seven received white noise and steady light as a sham. Both groups used the devices about 90% of the time as instructed, and no severe side effects were reported.
By the end of the study, the treatment group showed stronger connectivity between brain regions tied to cognition and visual processing than the control group. Treatment participants also performed better on a memory test that required matching faces with names. Two measures linked to Alzheimer’s progression reduced hippocampal volume and increased ventricle volume worsened in the control group but did not change significantly in the treatment group. With so few participants in each arm, researchers cautioned against reading too much into the results.
What Sound Therapy for Alzheimer’s Could Mean for Patients and Families
The GENUS approach is also being evaluated in a nationwide clinical trial run by Cognito Therapeutics, an MIT spinoff. For now, the therapy is not a standard treatment, and the researchers behind these studies have been consistent about the limits of what small trials can prove. The MIT authors described their pilot as evidence that daily 40 Hz audiovisual stimulation is “safe, feasible and may offer cognitive and biomarker benefits in some individuals with mild AD, supporting further investigation.”
Two patterns from the research are worth watching as larger trials move forward. First, the benefits in the MIT pilot were concentrated in participants with late-onset Alzheimer’s the more common form of the disease that typically appears after age 65. Second, the two men with early-onset Alzheimer’s did not show significant benefits, raising questions researchers will need larger studies to answer. Whether sex, age of onset or disease subtype drives that difference is not yet clear from a dataset this size.
For families weighing what these findings mean today, the honest answer is that sound therapy for Alzheimer’s remains an active area of research rather than an approved treatment. But the studies signal a shift in how scientists are approaching a disease that has resisted decades of drug-focused work asking not only what proteins are doing in the brain, but how the brain’s own electrical rhythms might be nudged back toward health.
This article was created by content specialists using various tools, including AI.
