Based on PNAS 2026 & Nature 2024 Research

Download the sound
your brain has been
waiting for

If someone you love has been touched by Alzheimer's, or if you are thinking seriously about your own brain health as you age, you have probably gone looking for something you can actually do. Something grounded in real science. Something that fits into daily life without becoming another burden.

Gamma40 was made for that moment. Nine 60-minute ambient tracks, each delivering a precisely calibrated 40 Hz pulse. Put on headphones, press play, and go about your day.

200%+
CSF amyloid increase
after 7-day protocol
5 wk
Lasting effect in
primate study
670
Patients in Phase 3
clinical trial now
40
HERTZ
01 · What Is Gamma40

Made for the moment
you decide to do
something real.

It is a collection of nine 60-minute audio tracks, each one delivering a precisely calibrated 40 Hz auditory pulse embedded in a different ambient soundscape. You put on headphones, press play, and go about your day. The pulse is there with you throughout — a steady 40-beat rhythm running beneath the ambient sound, doing its work while you read, rest, or simply sit with a cup of tea.

The underlying research is real, peer-reviewed, and moving fast. Human trials are ongoing. We have built Gamma40 for people who want to engage with that science now, with clear eyes about where the evidence currently stands.

View the full research infographic →
The Science, Briefly

The brain naturally produces gamma oscillations at around 40 Hz during healthy cognitive activity. In Alzheimer's disease, these rhythms are disrupted.

Research from MIT's Tsai Lab first showed in 2016 that driving gamma oscillations externally using pulsed sound or light reduces amyloid load in mouse models of Alzheimer's. This approach became known as the GENUS protocol.

A 2026 study in PNAS (Wang et al.) provided the first primate evidence. After seven days of daily 40 Hz auditory stimulation, CSF amyloid levels in aged rhesus monkeys increased by more than 200%, indicating the brain was actively clearing amyloid via the glymphatic system. That elevated clearance persisted for over five weeks after stimulation ended — a duration unlike anything seen in prior rodent studies.

A 2024 study in Nature (Murdock et al.) confirmed the mechanism at the molecular level. Gamma stimulation triggers a chain involving VIP interneurons, arterial pulsatility, and AQP4 water channels in astrocytes, collectively driving glymphatic clearance.

Gamma40 tracks are built to match the exact stimulus used in the Wang et al. study: 1,000 Hz pure tones, pulsed at 40 Hz, at 1 ms per burst, at 60 dB SPL. Pulse frequency is validated at ±0.05 Hz by FFT analysis.

How it works
👁️🎵
Sensory Entrainment
40 Hz sound drives neurons to fire in synchrony at gamma frequency.
🔌
VIP Interneurons
That rhythm activates specialised nerve cells (VIP interneurons) that tell the brain's blood vessels to relax and open up slightly (vascular tone regulation).
💧
AQP4 Channels Open
Tiny water gates in the brain's support cells (AQP4 channels in astrocytes) open up, letting the brain's natural rinsing fluid (CSF) flow in much more freely.
🫀
Arterial Pulsatility
Your artery pulse now acts as a pump, pushing fresh fluid deeper into brain tissue while drainage vessels along the brain's surface (meningeal lymphatics) widen.
🧹
Glymphatic Clearance
The fluid sweeps through, picks up the sticky amyloid proteins (amyloid-β) that cause Alzheimer's plaques, and carries them out of the brain via the waste-clearance network (glymphatic system).
Key findings at a glance
200%+
CSF Aβ increase
After just 7 days of 1hr/day auditory stimulation in aged primates
5wk
Effect duration
Elevated clearance persisted weeks after cessation. Nothing like it had been seen in rodent studies.
76%
Cognitive decline reduced
vs. sham control in Cognito's OVERTURE feasibility trial over 6 months
670
Phase 3 trial patients
Cognito Therapeutics HOPE trial. The largest Alzheimer's device study ever run.
02 · The Tracks

Science-grade audio.
Works in any
music player.

Download once to your phone, tablet, or computer. Play in Apple Music, VLC, or any app that plays MP3 or M4A files. No subscription. No account. No algorithm.

  • ⬇️
    Download your track
    MP3 320kbps, M4A (AAC 256kbps), or lossless WAV. Play from your local music library with no streaming and no loudness normalisation altering your calibrated level.
  • 🎧
    Put on headphones
    Any headphones or earbuds work. Wired is ideal for precision. Set the volume until the tone beneath the ambient sound feels like a normal conversation at arm's length, roughly 60 dB.
  • ⏱️
    Play for one hour, daily
    Work, read, walk, rest. The ambient soundscape fits into any routine, and the 40 Hz pulse runs underneath without interrupting it.
  • 📅
    Same time each day
    Consistency matters more than timing. Set a daily alarm as your cue. The Wang 2026 primate study used daily 10am sessions, and the habit itself is as important as the audio.
⚗️
Not binaural beats. This is something different.
The market is flooded with "40 Hz binaural" tracks that create a phantom beat through the illusion of two offset tones. Gamma40 uses real acoustic 40 Hz pulses, the same signal tested in PNAS 2026 and the Cognito HOPE trial. Binaural beats have weak, inconsistent evidence. Pulse-train entrainment has a mechanistically confirmed glymphatic pathway. These are not the same product.
Gamma40 Library
9 TRACKS · 40HZ PROTOCOL · MP3 · M4A · WAV
🟢 2 free tracks included
NOW PLAYING
Rain on Leaves
1kHz · 40Hz pulse · 60 min · FREE SAMPLE
24:3360:00
  • 🌧️
    Rain on Leaves
    Soft rainfall · morning session
    60:00 FREE
  • 2 🔇
    Pure Pulse
    Raw 40 Hz protocol · no masking
    60:00 FREE
  • 3 🌲
    Deep Forest
    Birds, creek, rustling · focus work
    60:00 $5
  • 4 🌊
    Ocean Shore
    Waves, no gulls · evening wind-down
    60:00 $5
  • 5 🏞️
    River Stream
    Flowing water · gentle focus
    60:00 $5
  • 6 🟫
    Brown Noise
    Warm bass noise · deep focus
    60:00 $5
  • 7 🌌
    Atmosphere
    Ambient pads · deep rest
    60:00 $5
  • 8
    Stargazer
    Sparse tones · night listening
    60:00 $5
  • 9 🧘
    Peaceful Mind
    Meditation tone · slow breathing
    60:00 $5
Free Tracks
$0
Rain on Leaves & Pure Pulse
Two complete 60-minute sessions, free forever. Try the protocol, calibrate your volume, build the habit before you spend a cent.
Download Free
Full Library
All 9 tracks · best value
Every track in MP3, M4A, and WAV. A different soundscape for every mood and moment. Best value for committed daily practice.
Buy Bundle — $19
⚠ WELLNESS AUDIO — NOT MEDICAL TREATMENT
These are general wellness audio tracks. They do not diagnose, treat, cure, or prevent any disease. Evidence is promising but not conclusive. Consult your doctor if you have epilepsy, cochlear implants, or neurological conditions before use.
03 · Research Insights

Translating
neuroscience
for everyone

📊 Full Infographic ↗
🐒 Primate Study · 2026

The Monkey Study That Changed Everything

Wang et al.[1] exposed 9 aged rhesus monkeys (26–31 years old) to just 7 days of 40 Hz sound. CSF amyloid levels more than doubled and, critically, remained elevated for over 5 weeks after stimulation ended. This long-term effect had never been seen in any rodent study, suggesting fundamental species differences in how the glymphatic system responds.

Postmortem examination confirmed widespread amyloid plaques in all four examined brains, validating that the CSF changes were reflecting real pathological clearance rather than measurement artefact.

Read in PNAS 2026 →
Wang et al. · PNAS 123(2) · e2529565123
CSF Amyloid-β Level (pg/mL)
Baseline
Day 0
Pre-stim
+200%
Day 14
Post-stim
+201%
Day 49
5wk later
Higher CSF Aβ = more amyloid cleared from brain tissue into fluid
🧫 Mouse Study · 2024

Glymphatic Mechanism Confirmed in Nature

Murdock et al.[2] pinpointed the exact cascade: gamma stimulation triggers VIP interneurons → arterial pulsatility increases → AQP4 water channels in astrocytes open → CSF floods in → amyloid washes out. Blocking any step in the chain blocked clearance.

Nature 627, 149–156 →
Murdock et al. · Nature · 2024
👤 Human Study · 2025

2 Years of Daily Stimulation: Cognition Preserved

Chan, Tsai et al.[3] followed 5 mild AD patients for 30 months at MIT. Three late-onset patients maintained significantly higher cognition versus national AD databases. Two showed plasma pTau217 reduction, which is direct biomarker evidence of disease modification.

Alzheimer's & Dementia 2025 →
Chan, Tsai et al. · Alz & Dem · 2025
⚠️ Conflicting · 2023

Why the Rodent Debate Matters

Soula et al.[4] found that 40 Hz visual stimulation failed to entrain gamma oscillations or reduce Aβ in their AD mouse model. This important null result challenges the rodent evidence base, which is exactly why the primate data from Wang 2026[1] matters so much. We need species that actually develop AD naturally.

Nat Neurosci 26, 570–578 →
Soula et al. · Nature Neuroscience · 2023
🏥 Clinical Trial

HOPE Trial: 670 Patients, Phase 3

Cognito Therapeutics' Spectris AD device, a wearable 40 Hz audiovisual headset, is in the largest Alzheimer's device trial in history.[5] 670 patients, 70 US sites, 12-month treatment phase. Results expected 2026–2027 and will be definitive for whether this approach gains clinical approval.

NCT05637801 ↗
Cognito Therapeutics · HOPE Study · 2025–2027
🔬 Mechanism

Why Audio Reaches Deep Where Light Cannot

Martorell et al.[6] showed that the auditory cortex, sitting in the temporal lobe — the region most severely affected by Alzheimer's pathology — is activated directly by sound. Visual stimulation targets the occipital cortex instead. That anatomical advantage makes audio-first stimulation a compelling therapeutic pathway.

Cell 177, 256–271 →
Martorell et al. · Cell · 2019
References
  1. Wang et al. (2026). Long-term effects of forty-hertz auditory stimulation as a treatment of Alzheimer's disease: insights from an aged monkey model study. PNAS 123(2), e2529565123. doi.org/10.1073/pnas.2529565123 ↗
  2. Murdock et al. (2024). Multisensory gamma stimulation promotes glymphatic clearance of amyloid. Nature 627, 149–156. doi.org/10.1038/s41586-024-07132-6 ↗
  3. Chan, Tsai et al. (2025). Gamma sensory stimulation in mild Alzheimer's dementia: an open-label extension study. Alzheimer's & Dementia. doi.org/10.1002/alz.70792 ↗
  4. Soula et al. (2023). Forty-hertz light stimulation does not entrain native gamma oscillations in Alzheimer's disease model mice. Nature Neuroscience 26, 570–578. doi.org/10.1038/s41593-023-01270-2 ↗
  5. Cognito Therapeutics. HOPE Trial — pivotal Phase 3 study of Spectris AD in mild-to-moderate Alzheimer's disease. 670 patients, 70 US sites. NCT05637801 ↗
  6. Martorell et al. (2019). Multi-sensory gamma stimulation ameliorates Alzheimer's-associated pathology and improves cognition. Cell 177, 256–271. doi.org/10.1016/j.cell.2019.02.014 ↗
04 · Research Timeline

A decade of
gamma science

2016
The founding experiment: light entrainment reduces amyloid in mice
Tsai lab at MIT shows 40 Hz flickering light drives gamma oscillations and reduces amyloid in the visual cortex of AD mice. Launches an entire field of research.
Iaccarino et al. · Nature 540, 230–235
2019
Audio added: hippocampus targeted, cognition improved
Combined 40 Hz audio-visual stimulation reaches the temporal cortex and hippocampus, reducing plaques in these memory-critical regions and improving mouse cognition.
Martorell et al. · Cell 177, 256–271
2022
First human trial: safe, entrains hippocampus, reduces atrophy
MIT Phase 2A trial in 15 mild AD patients. 3 months of daily 40 Hz audio-visual stimulation reduced hippocampal atrophy, improved connectivity, and enhanced delayed recall. No adverse events.
Chan et al. · PLOS One 17, e0278412
2024
Glymphatic mechanism proven: AQP4, arterial pulsatility, VIP interneurons
The molecular mechanism is established. Blocking any step in the AQP4→arterial pulsatility→glymphatic clearance chain prevents amyloid removal. The system is now well understood.
Murdock et al. · Nature 627, 149–156
2025
2-year human follow-up: pTau217 reduced, cognition maintained
5-patient extension study over 30 months. Late-onset AD patients maintained cognition and showed significant plasma pTau217 reduction. The first direct Alzheimer's biomarker evidence in humans.
Chan, Tsai et al. · Alzheimer's & Dementia
2026
First primate study: 200% Aβ rise, 5-week persistence
9 aged rhesus monkeys. 7-day protocol. CSF amyloid doubles and remains elevated 5 weeks later. The strongest evidence yet that this works in species that naturally develop AD pathology, not just engineered mice.
Wang et al. · PNAS 123(2) e2529565123 · Gamma40 is built on this
2026–27
HOPE Phase 3 results expected: 670 patients, 70 US sites
Cognito Therapeutics' pivotal trial completes. This will be the largest, most rigorous test of 40 Hz stimulation in humans and will determine whether the approach gains FDA approval as a medical treatment.
NCT05637801 · Cognito Therapeutics HOPE Study
Start Today

One hour of sound.
A decade of research.
Your brain will thank you.

Download the free 10-minute sample, calibrate your headphones, and experience the protocol yourself. No app. No account. Just the science, in your ears.

🎧 Download Free Sample Track 🎵 Browse Full Library on Gumroad 📊 Research Infographic ↗
✓ MP3 320kbps ✓ M4A 256kbps ✓ WAV lossless ✓ Works on any device ✓ No subscription ✓ Yours forever

Gamma40 is a general wellness application. It is not a medical device and has not been approved by the FDA, TGA, or any regulatory body to treat, diagnose, cure or prevent any disease. Consult your physician before use if you have epilepsy, cochlear implants, or are under neurological treatment. Evidence supporting 40 Hz stimulation is promising but Phase 3 clinical trials are ongoing.