Can Listening to Sound and Watching Light Put the Brakes on Alzheimer's Progression?

Alzheimer's disease (AD) is a neurodegenerative disorder that primarily affects older adults and is the most common cause of dementia.

What if there were a method that only required one hour of flickering light and one hour of buzzing sound at home each day to slow the progression of Alzheimer's — would you be willing to give it a try?

In recent years, studies have suggested that 40Hz sensory stimulation (sound, light, etc.) may correct abnormal gamma wave activity in the brains of AD patients, thereby improving their clinical symptoms.

A study published in October 2025 in Alzheimer's & Dementia has provided the first answer. Led by Dr. Diane Chan, the study followed five patients with mild Alzheimer's disease for two years. Two years — 730 days — with one hour of stimulation each day, amounting to over 700 hours of intervention per person. This is unprecedented in the field of gamma stimulation research.[1]

All five participants were aware that they were receiving active treatment. These participants came from a previous randomized controlled trial (NCT04055376) and voluntarily continued with daily stimulation for approximately two years after completing the original trial.

LOAD: Lateonset Alzheimer's disease (onset age ≥65 years)
EOAD: Earlyonset Alzheimer's disease (onset age <65 years)

Participants used a 40Hz audiovisual stimulation device at home for one hour daily (the device consists of a 2foot square LED panel and speakers that synchronously deliver 40Hz light pulses and sound, paired with a tablet for entertainment). Assessment tools included:

Electroencephalography (EEG): to evaluate 40Hz neural entrainment

Neuropsychological tests: MMSE, CDRSOB, FAS, MoCA, ADASCog

Plasma biomarker: p- Tau217

Actigraphy: to monitor circadian rhythms and sleep

Magnetic resonance imaging (MRI): to assess changes in brain volume

The results were encouraging:

First, safety. For a full two years, one hour per day — no adverse events occurred. This is truly an intervention with "zero side effects."

Second, efficacy. The three patients with lateonset AD (onset after age 65) not only maintained good EEG responses, but their rate of cognitive decline was significantly slower than that of agematched controls.

Even more surprising — plasma p- Tau217 levels in two of these patients decreased by 47% and 19%, respectively. (p- Tau217 is currently one of the most reliable blood biomarkers for Alzheimer's disease; its level closely correlates with tau pathology in the brain.)

This is the first time anywhere that longterm 40Hz therapy has been directly linked to actual changes in Alzheimer's biomarkers.

The study also revealed an intriguing difference: the two patients with earlyonset AD (onset before age 65) did not respond as well as the lateonset patients. Their EEG responses declined after two years, whereas the lateonset patients' responses actually increased (by 109%, 164%, and 113%, respectively).

What does this mean? It means that not everyone responds the same way to this therapy. Just as some medications work well for certain people but not for others, 40Hz therapy may also require a "personalized" approach.

If you or a family member is suffering from Alzheimer's disease, this news means:

A new hope is emerging. This is not a cure, but it may be the first nonpharmacological therapy that truly "hits the brakes."

A self- administered option. No hospital visits, no injections, no pills — all done at home.

A reminder: intervene early, act early. The patients in the study all had mild Alzheimer's. As with all neurodegenerative diseases, the earlier the intervention, the better the potential outcome.

[1]Diane Chan, Gabrielle de Weck, et al. Gamma sensory stimulation in mild Alzheimer's dementia: An open-label extension study. Alzheimer's Association. October 2025 Volume21, Issue10

https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz.70792