[pmoriarty]

After hearing this intriguing RadioLab episode some months back, I started searching around youtube for 40 Hz tones and found quite a lot of videos of all kinds that use those and other tones allegedly related to various brain waves (Alpha, Beta, Gamma, etc).

I listened to a whole bunch of these videos, and while I wasn't measuring my memory, I did pay close attention to how the sounds made me feel, and this one particular made me feel strangest: [1]. Unfortunately, the sound fades in and out and the effect goes with it. I wish it could have had stayed at a steady volume so that the effect could be sustained. If you watch it, just ignore the cheesy graphics and listen.

Here are some other interesting ones: [2], [3], [4], [5], [6]

Video [3] is actually supposedly 40 Hz.

[1] - https://www.youtube.com/watch?v=2-eTVW8VMRQ

[2] - https://www.youtube.com/watch?v=xG22hV-gMsY

[3] - https://www.youtube.com/watch?v=ZGHbKWGgH_E

[4] - https://www.youtube.com/watch?v=lhZPMTpW-gg

[5] - https://www.youtube.com/watch?v=9-yz8l4Do-U

[6] - https://www.youtube.com/watch?v=5lN3X5qVoqQ

[louthy]

[3] is definitely not 40hz. 40hz is in the sub-bass range, which this clearly isn't. I'm not at home in my studio right now, so I can't measure what it is, but if I was to guess it would be around 200hz.

The ones that are 20hz might make you feel a bit weird because there's not much amateur audio equipment that would do anything other than distort at that low end of the frequency range.

It does say binaural though, so maybe it's panning left/right at 40hz rather than playing a sound-wave at 40hz. If that's the case it's not the same as what the article states: "40 hertz tone".

Here's an online tone generator [1] that will play a sine-wave at 40hz.

[1] https://www.szynalski.com/tone-generator/

[roywiggins]

A lot of the binaural stuff try to set up "beats" by playing a slightly different frequency to each ear. Neither frequency is 40Hz, but the beat frequency may be.

There's an absolute shedload of woo-woo stuff on the purported consciousness-enhancing benefits if you google around. That's not to say they definitely don't do funny things to your brain. https://en.wikipedia.org/wiki/Beat_(acoustics)#Binaural_beat...

[pmoriarty]

"That's not to say they definitely don't do funny things to your brain."

Exactly.

I actually just went in to Ardour and edited down that one "20 Hz" video I mentioned made me feel weird [1] so that it played the loudest part continuously instead of fading in and out, and then listened to it again and after 5 or 10 minutes of listening to it I felt really weird again, and started to get worried about what it might be doing to me, so I stopped.

It's really interesting, though, and I hope some serious research is conducted on this sort of sound's psychological effects.

[1] - https://www.youtube.com/watch?v=2-eTVW8VMRQ

[duskwuff]

> There's an absolute shedload of woo-woo stuff on the purported consciousness-enhancing benefits if you google around.

Oh god, yes, and it isn't even new. Back around 2005, I ran into a web site selling audio files which they claimed would cure addictions, attract romantic partners, improve luck...

[joezydeco]

And, twenty years before that, this group claimed that binaural "synchronization" of the hemispheres of the brain could lead to out-of-body travel.

https://www.monroeinstitute.org/

I think they've backed down on some of those claims over the last 30 years, but they'll be happy to take your money for a 5 day onsite retreat.

[mattjaynes]

The youtube video creator addresses this in the description and comments:

"the base frequency is 183.58 and the "binaural beat" frequency is 40hz - meaning the difference in the left ear and right ear is 40hz. The left ear plays 183.58 and the right ear plays 223.58hz the difference being 40hz. "

[louthy]

Ah, sorry, I missed that. Still, I maintain that's different to what's stated in the article of "40 hertz tone". Which to me means a 40hz sine wave.

Perhaps the binaural effect does have some benefits, but personally I was struggling to listen to that video for more than 30 seconds or so without feeling both mildly sick and annoyed at the same time! However, I've been listening to the 40 hertz tone from the link I posted above for a good 10 minutes now without any bother. It's quite relaxing after a while actually.

[pbhjpbhj]

Szynalski.com has a page discussing the 40hz/plaque removal.

Another tone generator that I've used -- https://mynoise.net/NoiseMachines/isochronicBrainwaveGenerat...

I like binaural beats, some give me an ASMR like effect (ASMR videos made with binaural backgrounds b work well for me too).

[SubiculumCode]

That is pretty nice, but i note that they don't reach up to 40hz.

[SubiculumCode]

In the paper, "a 10 kHz tone was played at 40 Hz"

So its a high pitched sound played in 40 Hz bursts. Anyone have a generator for something like that? (though 10 kHz can be annoying)

[louthy]

Seems weird that the second value (40) is in Hz. It doesn't specify the duration of the burst, if it is in bursts. Is it once cycle of a 10 KHz tone 40 times a second, or more? Very odd.

[SubiculumCode]

or is that what binaural refers to?

[simongr3dal]

That first video definitely is giving me a strange sensation too, it's like my ears and nose are vibrating in response to the "beats" of the audio.