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Does listening to a 40 Hz tone “clean up” the brain in Alzheimer’s patients?

In 2012, I made a Web-based tone generator with the goal of helping tinnitus patients determine the frequency of their tinnitus to better target therapy. Since then, I have heard from people using my generator to teach physics, practice violin, drive away carpenter bees, tune DIY speakers, analyze room acoustics, calibrate vintage synthesizers, cause mischief in class with frequencies the teacher can’t hear, and even open a portal to Sedona, AZ. Far be it from me to take away from all these worthwhile applications, but last week, I got a message from Dennis Tuffin (of Devon, England), describing a new use for my generator which may very well trump everything else:

For the past 7 weeks I have been using your tone-generator for a purpose I wouldn’t think you had envisaged but about which I am sure you will be interested.

I have been following up on some research which my daughters had done about the treatment of Alzheimers by using a 40Hz flickering light source or alternatively a 40Hz sound source. There is sparse info on the net about these experiments though there is a recent piece about it. [here Dennis is referring to this paywalled article]

So I have been trying the sound therapy on my wife who is in the advanced stages of Alzheimer’s and to my surprise after 8 days she started to show small signs of being more mentally alert than before. So I have continued to use your tone generator using a 40Hz sine wave for about an hour each day. (I’ve recently started to do it twice a day for slightly shorter sessions). I found it necessary to connect external speakers to my laptop in order to pick up such a low note and to run it at a level of between 46-54 decibels so that she hears it wherever she is in the room. (Dementia sufferers get very fidgety!). So now 7 weeks on the improvement in her awareness has continued to the point where she is starting to be able to put a few words together and to respond to questions neither of which she has been able to do for nearly a year. Her odd physical habits have not been changed so far but she is definitely walking better and not shuffling her feet as she used to. Surprisingly, she is also sleeping better and not suffering as much with the sleep apnoea problem that she’s always had.

Photo of laptop and a small speaker on a kitchen countertop

The setup used by Dennis. The black box on the left is the external speaker.

Of course I expect there to be a limit to this progress as in the 8 years since my wife was first diagnosed her brain will have shrunk considerably so I do not expect her memory to return but on the other hand my wife’s quality of life has been improved.

To date I have not gone public on this and only close family have known but by the end of another week when it will be 8 weeks since we started I think I would like to spread the word and hopefully prompt a few professionals to do more proper research.

The science so far

  • It has been known since at least the 1980s that cognitive activity triggers brainwaves (wave-like patterns of activation) at a frequency of 40 Hz in humans and other mammals.
  • In 1991, researchers from the NYU Medical Center discovered that Alzheimer’s patients have reduced 40 Hz brainwaves compared with healthy people. (paywalled paper)
  • In 2016, MIT’s Alzheimer’s group did experiments on transgenic mice with early Alzheimer’s disease and found that exposing them to a light flickering at a frequency of 40 Hz (40 times a second) for 1 hour a day for 7 days causes an almost 60% reduction in β-amyloid plaques, which are a molecular hallmark of Alzheimer’s. Flickering at 20 Hz and 80 Hz did not have the same effect. An important qualification here is that the effect was limited to the visual cortex, which is not significantly affected in human Alzheimer’s patients. Here’s an accessibly written report in The Atlantic and here’s the original paper (published in Nature) if you’re strong in science-speak. MIT also made a video about the findings.
  • In March 2016, scientists at the University of Toronto published the results of a small, placebo-controlled pilot study (paywalled paper), in which they exposed 20 Alzheimer’s patients to a 40 Hz sound. After six 30-minute sessions (done twice a week), the patients’ average score on the 30-point SLUMS scale improved by 4 points, while the placebo group did not improve. It should be noted that the “dosage” of the treatment was rather low, which may explain the modest results.
  • In January 2017, Cognito Therapeutics, a company formed by some of the members of the MIT team, started conducting preliminary trials to assess the safety of exposing AD patients to simultaneous flickering lights, an audio tone, and vibrations – all at 40 hertz.
  • In January 2018, the New Scientist reported (paywalled article) that the same MIT team achieved even better results by playing mice a 40 Hz sound. β-amyloid plaques shrank by about 50% in the auditory cortex and – crucially – in the hippocampus, perhaps because the two areas are close to each other. This would be a very important discovery, because the hippocampus is the region of the brain which is involved in forming memories. It is the hippocampus that suffers the most damage in human Alzheimer’s patients. According to the magazine, these results were presented at the Society for Neuroscience conference in Washington in November 2017. However, the published paper described a significantly different protocol (see below), so it is likely that the New Scientist didn’t get the details right.
  • In July 2018, the International Journal of Alzheimer’s Disease published the results of a pilot study in which 6 human patients were exposed to a 40-hertz flickering light bulb for 2 hours a day for 10 days. The therapy was administered in a home setting by the patients’ caregivers. No difference in β-amyloid plaque was found after therapy. If there was an effect, it must have been smaller than 20%, which is not comparable to the 50% reduction seen in mice.
  • In March 2019, Cell published another (paywalled) paper about another study done by the MIT group. Here’s a NYT article about it. Here are the main points:
    • After mice were exposed (for 7 days, 1 hour a day) to a series of clicks repeating at a frequency of 40 Hz, the amount of amyloid plaque in their auditory cortex and their hippocampus was reduced by about 40%. The mice also did better on several tasks involving the use of memory.
    • The clicks were 10 kHz waves, 1 millisecond long, repeated 40 times a second (each cycle had a 1 ms tone followed by 24 ms of silence). In communication with me, one of the paper’s authors said that pure 40 Hz tones were not used because mice cannot hear tones of such a low frequency.
    • When this auditory treatment was combined with light pulses at 40 Hz, microglia (“brain cleaner cells”) started clustering around amyloid plaque, and the reductions in plaque extended to parts of the prefrontal cortex (an area related to functions like attention and short-term memory). This effect was not observed with either audio or light treatment alone.
  • In 2018, Cognito Therapeutics started three clinical trials of their device (called “GammaSense”) that combines visual and auditory stimulation. The device is essentially LED goggles with over-the-ear headphones.
  • [NEW] In 2019, Dr Tsai’s MIT group started two small trials of another device – a white screen illuminated with LEDs flashing at 40 Hz combined with a soundbar emitting a 40 Hz “buzzing” or “humming” sound. Here is a summary of Dr Tsai’s presentation on it and here are the pages for the two trials on
  • [NEW] In April 2021 at the AD/PD conference, Cognito presented preliminary results of the GammaSense trials, most notably, the Overture trial (news story from, which is designed to evaluate efficacy. 46 patients with Alzheimer’s Disease received a daily 60-minute session with the GammaSense device for a period of 6 months. The control group comprised 28 patients who received sham treatment (i.e. a placebo-like device that isn’t supposed to do anything). The study seems to tick all the boxes for good scientific research: it’s randomized and multi-center. Although it’s not strictly double-blind, the subjects, their caregivers and the people who rated the patients’ cognitive functions were blinded (i.e. they did not know who has received real treatment and who the sham). Back when this trial was announced, I wrote that it was rather small and the only way it could show anything is if the device had a large effect. Well, the results are decidedly mixed, and I can pretty confidently say that GammaSense didn’t have the sort of huge effect everyone was hoping for. There was no significant difference between GammaSense and placebo on 3 out of 5 cognitive tests used in the study, and GammaSense came out slightly ahead on two of them. Brain tissue loss also seemed to be slower in the treatment group, though that doesn’t have to mean anything, considering that the control group was older than the treatment group. I would definitely like to see a proper, peer-reviewed paper rather than just a presentation – someone should go over Cognito’s work and make sure the results are statistically valid. The researchers collected amyloid PET scans, CSF, and blood samples, but have yet to analyze them. I do like the fact that cognitive function was assessed, not just amyloid deposits – we already have experimental drugs that remove β-amyloid, but don’t do anything when it comes to actual dementia. Too bad the results have fallen short.
  • Cognito is not giving up and has announced another, larger study, which is to start in the second half of 2021.

Further reading/listening

Update from Dennis (March 2020):

I’ve gotten in touch with Dennis Tuffin to ask about his long-term experiences with 40 Hz therapy. Here is his response:

I reached a point when I knew that my wife’s condition was worsening so after [about 8 months] I gave up using the sound treatment. (…) My wife was already losing verbal capacity and was decidedly becoming slower in her movements, so it’s not the case that stopping the treatment caused these things as they were already happening. I was enthusiastic about it, because there appeared to be a noticeable improvement in her capabilities for that 8 or 9 month period, so noticeable that it was remarked on by almost everyone that she knew. So I am still sure that it helped, if only for a limited period and I think that it’s also likely that if it had been applied from the beginning of her diagnosis it may have had an even longer lasting effect. I’d still say give it a try – it costs nothing.

Dennis also told me that he had recently learned that his wife has vascular dementia in addition to Alzheimer’s Disease. I mention this, because that fact might have some bearing on the effectiveness of sound therapy.

(Don’t) try this at home

Let’s say you are not dissuaded by the lukewarm results from the Cognito trials. You’ve decided that you’ve got nothing to lose and you want to try some kind of do-it-yourself auditory therapy. What kind of tones should you use?

Dennis, the reader from the UK who piqued my interest in this subject, used a pure 40 Hz tone.

According to this AlterNet article (later reprinted by The Salon), a pure tone was used in the preliminary safety study done by Cognito in early 2017.

It appears that the most recently published MIT study on mice used series of clicks (despite previous reports) rather than tones. The New York Times quotes Dr. Tsai, who worked on that study, as saying “your brain seems to be able to perceive clicks more than a tone”, which would seem to indicate a preference that’s not exclusive to mice. However, in response to my inquiry, another co-author of the paper, Ho-Jun Suk, said that 40 Hz pure tones were not used because mice cannot hear tones of such a low frequency.

The New York Times and the Boston Globe published articles about the MIT mice study, including links to audio samples of the stimuli that were used by the researchers. Unfortunately, I have discovered that neither sample represents accurately the audio waves that were played to the mice. The clicks in the published samples are smeared in time (closer to 2 ms) and are not pure 10 kHz tones. Ho-Jun Suk has confirmed that they do not match the source signal. (I don’t know how the NYT and Boston Globe managed to mangle the files so badly, but it’s not because of compression – I tried it on the same encoder and the same parameters that were used by the NYT and it did not distort the signal very much at all.)

This 2021 report from Alzforum uses the words “hum” and “buzz” (interchangeably) to describe the sounds used in the two ongoing MIT trials of the screen+soundbar device. This would seem to indicate that those trials use a pure 40 Hz tone, as a series of clicks doesn’t sound like humming or buzzing. Furthermore, it is reasonable to assume that if the researchers wanted to play a simple series of clicks, they would have used a smaller and more economical speaker, not what is described as a “high-fidelity soundbar”. However, the same article uses the word “buzz” when discussing the 2019 mice study, and we know that one used clicks, not tones, so we should be careful about how much we infer from the phrasing in that particular report.

If you are thinking about using clicks rather than pure tones, I would not recommend using 10 kHz clicks because human ears are not very sensitive to that range of the spectrum. Something like 3 kHz (where human hearing works the best) would probably be more sensible.

It would be very interesting to know what sort of tones are being used in the now ongoing human trials. (If you are in the trials or know anyone who’s in them, please let everyone know in the comments section.)

Technical advice for playing pure 40 Hz tones

A series of clicks is not particularly demanding – it can be played on anything. If you want to try playing a pure 40 Hz tone to someone with Alzheimer’s, here’s some technical advice:

Getting a 40 Hz tone is easy – you can use my frequency generator. (Please note I do not take responsibility for the purity of the produced tone, as it is generated by your Web browser – though I think it should be fine. By the way, I am also not a doctor and I am not giving medical advice or offering any medical product here.)

You will need decent speakers. 40 Hz is a very deep bass tone – the kind of rumbling tone that you feel in your body as much as you hear it. Small speakers, such as laptop speakers or small computer speakers, don’t go that low. If you try anyway, you will either hear nothing, or you will hear mostly – or only – distortion. What is distortion? It’s a higher-pitched, buzzing noise that speakers make when you push them too hard.

Photo of a bookshelf (monitor) speaker

A bookshelf speaker (photo: D. Cedler)

Bookshelf speakers will do 40 Hz, but their output at that frequency will be significantly reduced, so you will need to turn up the volume significantly, and they will produce easily audible distortion. Because the ear is more sensitive to high frequencies, the distortion may be subjectively louder than the fundamental 40 Hz tone (!), and may make the sound harder to tolerate, thus limiting the volume (and possibly the therapeutic effect).

The best solution is a high-quality subwoofer. It won’t be distortion-free, but you can expect the distortion to be 2–3 times quieter than with bookshelf speakers. This will give you as pure a tone as you can get. If you don’t care about playing music, you can get just a subwoofer (without any other speakers) and connect it to your computer or mobile device.

A neat trick to amplify the bass output of any speaker is to place it against as many walls as possible. For the maximum boost, put the speaker(s) on the floor, in a 3-way corner between two walls and the floor – that way, it will be adjacent to three surfaces.

How important is sound quality? It’s hard to say. Dennis seems to have had great results with cheap computer speakers. It is not known to what extent the therapeutic effect depends on volume or the presence of distortion. On the other hand, if you use small speakers, it won’t be obvious whether they’re actually playing 40 Hz or just distortion – so it’s worth getting something bigger just to be on the safe side.

Can you use headphones instead? It’s hard to say with certainty, as a 40 Hz tone played through your speakers will not just be heard with your ears – it will also be felt in your whole body. With headphones, the effect is strictly auditory. However, so far I haven’t seen any specific scientific reasons to suggest that this difference is important, and in fact headphones were used in the initial safety studies commissioned by Cognito. If you decide to use headphones, make sure they can do 40 Hz. The earbuds that came with your smartphone are probably not the way to go here. HeadRoom has a database of frequency response graphs for high-quality headphones, so you can check how loud a given model is at 40 Hz. Want a specific recommendation? Get the Koss Porta Pros (, They’ll do the job, they’re the most comfortable headphones I’ve used, and – at $40 – they’re tremendous value.

Call for comments

If you or your loved one has Alzheimer’s disease and you have tried 40 Hz sound therapy, please share your experiences – whether positive or negative – in the comments section below.

180 Comments so far

  • Chris

    Hi, Thanks for this! very interesting articles here.

    Has anyone tried with a Deep Didgeridoo?

    Here’s a recording of one that was crafted to resonate at 40 hz.

    It’s a free track on bandcamp >>

  • Power

    Thanks for a great summary on an important topic. I have used several online 40hz tracks. The two that have worked best for me are:
    and the original clicking track (allegedly) used in the MIT study:
    I’d be interested in your view of whether either of these youtube recordings actually represent a 40 Hz frequency! I use garden variety wired earbuds to listen on my smartphone.
    I use these as a 50-something individual who, like most of us in midlife, has experienced “subjective cognitive decline”, meaning I personally can discern that the old noggin is getting cobwebs, but have not been diagnosed with any official cognitive impairment. Since cognitive diseases including dementia and Alzheimers are progressive, early intervention, even to ‘clean out the cobwebs’ may help forestall or foreclose these ‘clinically official’ diagnoses that can come with time. It may be ‘too little, too late’ to start only once into advanced Alzheimers (imho).
    My results: I listen at night for about an hour before falling asleep (and sometimes fall asleep during). I get almost instant clarity the next day. Quicker thinking, reading, and verbal acuity; a general feeling of ‘hey, this is how my brain function felt about 10 years ago!’ Strangely, if I use it too frequently (say every single night for several weeks on end) it may become counterproductive, and I wake up feeling slightly fatigued with less clarity. So I take a break for a while before starting up again, and again notice almost immediate benefits in cognitive acuity.
    I would love your thoughts on the above two tracks, and on whether you have found better options?
    Thank you.

    • Tomasz P. Szynalski

      I checked the the first YouTube track and it’s not a pure 40 Hz tone – there is some noise and harmonic overtones added, which are quite audible. But it does contain mostly 40 Hz.
      I think it’s possible it simply helps you fall asleep better (and that any other frequency, say 50 Hz, would work just as well) and the cognitive improvements you’ve experienced are just due to better sleep. I know I feel a whole lot sharper when I get a good night’s sleep!

      • Power

        …or, maybe “mostly 40 hz” is good enough to stimulate a biological response. I don’t have problems sleeping or feeling refreshed on waking generally (ie. without listening to the tracks) so that’s not it.
        It is a noticeable difference from just sleep rejuvenation, and most definitely attributable to the listening – that said, I’ll try to find a ‘purer’ 40 hz for the long term. Any thoughts on the usability of the second track? (MIT one)

        • power

          …or will try your tone generator. Thanks so much

        • Tomasz P. Szynalski

          I doubt that a purer 40 Hz tone will make a difference; after all, it will still get mixed with sounds in your environment, so it will never be totally pure.
          About the “MIT” track, I don’t have anything to say other than what I’ve already written in the blog post and the comment section.

    • tom hunt

      you seem to think the mit clicks are the alleged sound recorded by MIT
      i presume the clicks are higher frequencies to mask the lower tone of 40Hz

      anyway, since i sense some skepticism on your part if these were the true clicks used, have you found a tract clicking with 40 Hz that you do trust as being effective and really 40Hz? if so would you send me a copy?

      i listened to the one from MIT for less than a minute, and when i took off the cheapest headphone ever made. i heard a diminishing tone for a minute that did not exist before i turned on the tract with clicking
      thanks for doing all the work

    • Kaarol

      I would also love to know whether the YT quoted sound from MIT (clicks) is fully the same as applied by MIT to mice (so we can rely on it) or not… Does anyone know for sure?

  • Mack Winston

    For clicks you don’t really need to overthink it – just use a square wave rather than a sine wave. A 40 Hz square wave will also have the higher frequency components (a square wave after all is a composite of the fundamental frequency (in this case 40Hz) and each odd harmonic, each one 1/3rd of the amplitude of the previous). So even if you can’t hear a 40Hz pure sine wave well, you’ll hear a 40Hz square wave very easily.

  • Brendon

    One study I found researching the effect of 40hz on Fibromyalgia used low frequency audio transducers instead of speakers. This is ideal because any surface can be made to vibrate with a transducer. The vibrations will penetrate the body more thoroughly than speakers and headphones. They are cheap and easy to set up, I am waiting for mine now and will start experimenting on myself and my mom who is in the late stages of Alzheimer’s. I will attach them to a plywood board and secure it to my box spring mattress.

  • Arc

    🙂 Do you also have any other information collected (- in link bibliography catalog) trying to scientifically confirm certain magical properties of other specific frequencies? For example, will tuning to 44Hz be healthier than tuning to 36Hz? What does serious science say about musical phenomena that evoke overwhelmingly positive or overwhelmingly negative reactions? There are certainly many publications describing the destructive effect of noise on the human body. So what will these frequencies or their combinations be? (Parana-science sometimes tries to replace science as we know.)

    • Tomasz P. Szynalski

      I don’t know anything about that.

    • Rob

      Arc, Why don’t you read the research by serious scientist Li-Huei Tsai of MIT on her work with 40 Hz frequencies to possibly treat Alzheimer‘s Disease. Or the work of other serious researchers at work Emory University and Georgia Tech who are studying the same phomenon. Their work is referenced the the comments here. So you might want to do that before coming on as the big cynical skeptic. Process the information presented, reflect….then comment.

  • Ben

    Have you or anyone else found anything about the effects of 40Hz binaural tones? There’s a lot of fun? interesting? binaural “experience” tracks out there, but their tones usually vary and claim to take listeners on a journey of some kind. While I can’t say I’ve experienced much from said tracks, I can say the nature of binaural beats feels much more “internalized” or more “in my head” than traditional tones.

    One downside to binaural beats is that you’ll need headphones to make them “work” but because they seem to be designed through L+R tone signal cancellation, as I understand it, you wouldn’t need 40Hz capable speakers to generate the experience of the same tone inside the head. Similar to the mouse tracks, you could make a 40Hz binaural track from something in the 3Hz spectrum (or any spectrum really)

    I noticed none of the research articles linked here mention binaural sounds, which I thought was interesting, but maybe it’s because they don’t work the same? Yet plenty of people claim these signals work great for concentration, relaxation, alertness, etc…

    Anyhow, it was something that popped up in my mind as I read through this article and associated commentary.


  • Gregory Whitchurch

    I’ve posted earlier (2019) about my Mom — we all thought this helped her somewhat.

    Here’s an interesting report on current research:

    Tx, Tomasz

  • Mark

    Hey there, I’ve got a question about generating the tone..
    What about just humming the tone? It shouldn’t take longer than a few min for someone to feel the tone and match it perfectly.
    It makes me think about yogis humming during meditation.
    I could feel 40hz before I even heard it just because it feels like a natural vibration.

  • Kaarol

    Does anyone know whether the light and sound must be in perfect sync?

    • Ted Matsuda

      If the phase of the light and sound waveforms exceeds 90 degrees, it may cause symptoms such as “discomfort and severe drowsiness accompanied by strong headaches.”
      It may be dangerous if you don’t use quality-controlled manufacturer’s products that have properly completed clinical trials.

  • Sopranome

    Will a Bluetooth subwoofer produce 40 hz frequencies accurately? Someone told me (insisted actually) that it will not. I am thinking about applying this technology, just wondering whether I need to get a subwoofer which has to be attached by cable to my tablet.

    • Tomasz P. Szynalski

      Any subwoofer will produce some 40 Hz. The difference between a good one and a bad one is the volume and how pure the sound is (a bad one will have large amounts of extra frequencies layered on top of it). Bluetooth is just a mode of transmission – you could have a good subwoofer that’s connected by Bluetooth. There is nothing in Bluetooth that makes it impossible to produce a 40 Hz sound. A good subwoofer must be large – can’t get around physics.

    • Matthieu

      There are apps for smartphones to check what frequency is being produced. I am using “Sonic Tools” – of course i don’t know how accurate those are. But it seems quite pro for my taste 😉

  • Larry Walton

    Is this still an active blog??

    I’ve been playing around with 40 Hz gamma frequency for about 6 months now. I first heard about it on NPR science radio show. Dr Tsai of MIT, the one interviewed, seems to be a prominent player in the field. She’s also one of the founders of Cognito Therapeutics (“CT”), a spinoff of MIT’s Aging Brain Initiative. On Jan 26th, 2023, CT was issued a US patent (#US20230022546A1). The patent application gives an exhaustive description of the technique used in Tsai’s lab. The flashing/buzzing circuit itself is an extremely simple device. FDA response to CT’s latest study was to assign it a “Breakthrough Technology” label and put it on the certification fast track.

    I’m a retired high school STEM instructor. On a whim i decided to whip up something to emulate the patent, to understand more about possible effects on an old man like me. Frankly, I was stunned.

    As I say, it’s a very simple circuit, great as a beginning project for STEM students. I used an Arduino microprocessor board popular on the web and in the STEM classroom. Whole thing cost about $16.

    After using it for about 10 days I became so enthusiastic I made one for each of my daughters (one with autism, one with dysautonomia). Later I asked them to return the units in order to update the software. Their response was to refuse to give them back.

    Now I’m making units for friends. Anyone in my circle who shows an interest gets one for free – in an attempt to get feedback from other users. Can’t make them fast enough. Friends seem to fall into 2 camps: one side thinks I’m silly and am simply trying to sucker them into a new type of snake oil, the other side willing to give it a try. Of those who try it I’m getting 100% ongoing feedback recruitment rate.

    I saw a remark from one of the venture capitalists who seed funded CT ($73 million!). He said eventually it will probably prove not to work – over 99% of exciting research from mouse studies turn out to be non-transferable to humans – but on the extremely low probability of success he says it’s in the realm of Nobel Prize stuff. No doubt an overstatement but still impressive, eh…

    I hope this thread stays active. Thanks a bunch to Tomasz for really good writeup…

    • Curious30hz

      Can you provide an update on your device and tell us the details about materials and construction so we can make one if it actually ended up working?

      Thank you so much.


    • Tomasz P. Szynalski

      Hey Larry,
      Thanks for mentioning the US patent. According to this, the patent was issued in 2019, if I’m reading it correctly. What kind of waveform are you using in your device? At first glance, I can’t find any specifics in the patent application.

    • Matt Schneider

      Hi Larry,

      Pretty exciting project you have going. I’ve got a 94 year-old mom with mid-stage dementia. She lives in a assisted-living place with a similar group of people. Plenty of opportunity for feedback if you are interested.

      Would you please tell us what kind of response are you getting from users? For instance, what benefits do your daughters describe getting from use?

      Thanks for sharing your work with us!

    • Anon


      Can you provide any further details with regards to construction of your device (for us non-engineers) and also expand a bit on the results your daughters obtained?



  • Anon

    Here is a description of the device that I think Larry Walton is using:

    Excerpt –

    Sensory stimulation

    Sensory stimulation was delivered using a white light LED panel (2’x2’, correlated color temperature 3900-4000K = natural white color) that was modified for flicker and brightness control (Neltner Labs, Boston, MA) and a sound system (SB2920-C6, VIZIO, Irvine, CA; or LP-2024A+, Lepy connected to BRS40, BOSS, Hamamatsu, Japan; Fig 2A). For the visual stimulation, both the control (constant white light) and active groups (40Hz light flicker; Fig 2B) received average light intensity around 390–400 lux at the participant’s eyes. For the auditory stimulation, the 40Hz sound was 78dB (cognitively normal group) or 68dB (patients with mild AD or epilepsy), with a 1ms rectangular pulse in each 25ms interval (4% duty cycle, 24ms isi; Fig 2B). The control sound was white noise at 68dB. The LED panel and the speaker were controlled by a custom circuit board that housed a Teensy USB Development Board (version 3.6, PJRC, Portland, OR).

    Picture of the device used in the study:

    Looks somewhat simple to build.


  • James Perry

    Do you think it is safe to try using 40Hz (audio &/or visual) stimulation for someone diagnosed with Vascular Dementia. Mother-in-Law has been diagnosed with this (but possibly also mixed with Alzheimer’s). I did purchase a light bulb that flickers at this rate and downloaded some 40Hz isochronic brainwave entrainment from YouTube. However, a thought occurred to me that, since vascular dementia involves reduced blood supply, by increasing overall brainwave activity to Gamma levels, might this put a strain on the damaged vessels and might do more harm than good. Could there be any validity in that idea?

  • Ted Matsuda

    Our company conducts research and development to improve clinical equipment for GENUS treatment with safe quality control, in Japan.

    Regarding the cases of vascular Mild Cognitive Impairment (MCI) in the prodromal stage of vascular dementia that we are currently investigating, there is a case in which symptomatic treatment has been effective in temporarily recovering from cognitive decline caused by loss of motivation after stroke. We are conducting preliminary studies with the goal of starting clinical trials within 5 years.
    Conversely, we also found test conditions that caused dangerous adverse events when GENUS stimulation was applied to patient with cerebrovascular disease. Based on this knowledge, we conduct research and development to improve GENUS clinical treatment tools with safe quality control.

    In particular, please pay attention to the following points.

    1) We recommend the use of “appropriate medical equipment” whose light and sound waves are precisely phase synchronized. If you manufacture the device at your own risk, please refer to the document below regarding “Safe Standard Waveforms”.
    “Gamma frequency sensory stimulation in patients with mild Alzheimer’s dementia: results of a feasibility study and pilot studies”

    2) In cerebrovascular stroke patients, approximately 10% of patients are known to develop symptoms epilepsy.
    “A comprehensive view of post-stroke epilepsy”

    GENUS uses light and sound stimulation to activate the patient and force the generation of brain waves. So we recommend to work with epilepsy specialists to observe with caution that epilepsy does not occur during GENUS activation.

  • Anon

    Is there a version of this device that can be purchased online?



  • Ted Matsuda

    Contrary to your wishes, our device cannot be sold until it has been approved by the Japanese health authorities as a “programmed medical device.”

    Even if we are able to start clinical trials in 5 years as planned, I think it will take 10 to 15 years to pass the Japanese government’s extremely rigorous review of various aspects such as adverse events and quality control.

    The best way for you will be to approach the health authorities and medical universities in your own country and petition them to conduct follow-up research on MIT’s GENUS.

    If you do so, the GENUS clinical trial will be conducted in your country, and you will have the opportunity to apply as a candidate for the clinical trial using medical devices developed in your country.

    It’s easy to make your own device, but unless you’re willing to risk your own life if the prototype fails, as I was, you’ll have to deal with adverse events caused by equipment malfunction. The cooperation of doctors and specialists is also essential.

    I am not developing equipment for the purpose of “making money” or “money games”, but rather I am working hard for the “Quality of Life” of many people, including myself.

    I am already old and have a short life expectancy, so I may pass away before I can commercialize this device.

    Still, as a Japanese engineer and researcher, I intend to continue a “kamikaze attacks (=efforts towards practical application) ” against “the enemy of humanity: dementia.”

  • Frank Yin

    What if the sound is not purely at 40Hz? Does it still work?

  • James E Vining

    More pf a question rather than a comment. I have the ability to reproduce (down to 32 Hz at a quite high SP)L Approx 105 dB.
    Is there a recommended Level (Volume) found to work the best?
    Sadly on 10-20-23 my father passed away at 77 after many years of suffering from Alzheimer’s. I figured having my Pro audio system all set up to have proper level as well as the proper Tones could help me if I f ind I start having any symptoms as well as helping others that may be interested in using sound to help with healing as well as improving mood and health in general.

  • James E Vining

    I forgot to mention or detail the Pro audio system I was referring to (Pro Audio is the quality and power of a system that can and is used to do live music ) or concerts consisting of 2 @ 15″ Subwoofers able to reproduce 20Hz easily as well as 2 @ Peavey Commercial series 1000X amps (Bridged) powering each 15″ Sub
    Each speaker can handle 1500 watts Max and each CS 1000X amp can output 1500 watts in bridged mode.
    Honestly if I were to attempt to run system at 75% power and up it causes stuff to fall from ceiling and in time would eventually vibrate the house apart.

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