I occasionally play with Gnaural, Audacity, and a couple of other programs in an attempt to create some interesting, if not useful, binaural recordings. I don’t have a technical background and a result, some of my questions may seem elementary, ignorant, or naïve. At any rate, here goes.

I have a partial understanding (particularly when thinking of 2 simple sine waves) of constructive and destructive interference, and beat frequencies. It appears to me that the binaural beats we use don’t actually involve physical interference of waves, but a neurological or subjective interpretation of the combination of waves coming into each ear separately.

The first question has to do with multiple frequencies (more than 2) and the resulting beat frequencies. For instance, if I combine sine waves of 100 Hz, 105 Hz, 400 Hz, and 405 Hz, what are the subjective or neurological effects? I’m assuming that 100 Hz and 400 Hz are being sent to one ear, and 105 Hz, and 405 Hz to the other.

The second question is whether the beat frequencies (5Hz) can be either in or out of phase, and if so, what would be the effects if they were 90 degrees (for example) out of phase?

The third question is if one sends sine waves of 100 Hz and 400 Hz to one ear, and 105 Hz and 404 Hz, to the other, what might one expect? In this example we are supposedly combining one internal beat frequency of 5 Hz and another of 4 Hz.

Finally, can combined beats interfere with each other and create a third beat?

All responses will be appreciated. Thanks.

Hi Dedogrande and welcome to Tom's MBT discussion forums. I don't know any answers to the technical stuff but as I understand Hemi-Sync the point is to have the two different waves become a third wave in your brain.
Love
Bette

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All That Is
what is?
Consciousness.

Dedogrande,

Since you are talking about entrainment of neurological effects as opposed to driving a physical system such as a membrane with sound, I don't really think that phase applies. You could try it on yourself. If you get back to us, we will know you survived and it was not a deleterious effect in any case. Such things are probably common in music although transient so unlikely to be harmful. My intuitive reaction is that it is not likely to be effective but I don't play around with these things.

Ted

Welcome to the forums!

1. I know that Hemi-Sync combines multiple beat frequencies on different base frequencies. I haven't seen it discussed much, but if The Monroe Institute started doing it they must have found it subjectively/neurologically beneficial. On the other hand, Tom wrote a post (see link below) about creating your own binaural beats and he only mentioned using a single beat with a single base frequency... so it may be unnecessary.

2. They can be out of phase and you will still get a beat. You may have a shift in the phase of the beat, but from a practical standpoint that doesn't matter. I've listened to binaural beats through speakers, where there is obvious interference and phase shifting, and there is still a subjective effect on me (although not as good as using headphones).

3. See 1 above. You'll "entrain" your brainwaves to peaks at 4 Hz and 5 Hz. It encourages both, but it's not like your brain is ONLY outputting those frequencies.

4. I'm not 100% sure what you mean by this, so I'll take my best shot. I don't think the 4 Hz and 5 Hz beats would interfere as they're already "outputs" from the interpretations of your ears and brain. The 100 Hz tone in the left ear and the 405 Hz tone in the right ear are too far apart to create another beat.

That's my limited understanding and I could be wrong.

You can read more about it here:

viewtopic.php?f=11&t=5056
http://en.wikipedia.org/wiki/Beat_(acoustics)
http://en.wikipedia.org/wiki/Binaural_beats

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Mike

Dedogrande, I was also trying to find some specific information on multiple frequencies for binaural beats, but didn't really find what I was looking for. The simple case of BB makes perfect sense to me - send 100 Hz to one ear and 104 Hz to the other ear and you get a beat frequency of 4 Hz which is at the low end of Theta frequency range.

What I am not clear on is what happens when you start trying to add additional frequncies. I believe the idea as has been stated by other members is that I may want to for example add some 20 Hz Beta waves to go with my 4 Hz Theta, presumably to keep me awake while in deep Theta. I can send 200 Hz to one ear and 220 Hz to the other ear to give me a 20 Hz Beta BB. If I send both 100 Hz and 200 Hz to one ear and then 104 Hz and 220 Hz to the other ear, supposedly I will get a simultaneous 4 Hz Theta BB and a 20 Hz Beta BB.

The frequency analysis of the Monroe Focus Levels as described in some of the binaural beat apps shows these multiple simultaneous frequencies so I have to assume there is something beneficial to this over just a single 4 Hz BB. Tom has not discussed multiple BB frequencies to my knowledge, but only ramping down to a single 4 Hz beat. Since the Monroe Explorer Tapes contain sessions from Tom (TC Explorer) in Focus 12 which is made up of these multiple frequencies, I continue to assume there is something to the multiple frequencies.

What I do not understand is if you have multiple frequencies such as 100 Hz and 200 Hz in one ear and 104 Hz and 220 Hz in the other ear, why would the brain entrain to 4 Hz and 20 Hz (104 - 100 and 220 - 200) and not say 120 Hz and 96 Hz (220 - 100 and 200 - 104)? Basically, as you start mixing frequencies, it seems random as to where the BB differential will occur.

I am also curious on multiple BBs of say 4 Hz. Is there any benefit to having a single 100 Hz - 104 Hz differential as opposed to layers of 4 Hz differentials such as 100 Hz - 104 Hz, 200 Hz - 204 Hz, 500 Hz - 504 Hz which would give you three seperate 4 Hz differentials? Also, why wouldn't the frequencies mix randomly?

Has anyone on this forum really gotten any better results using multiple frequencies as opposed to a simple single 4Hz differential?

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Yhni

Sounds like you've crossed into the Land of IP (intellectual property) - I would guess this is in part at least why The Monroe Institute has their patents.

Come to think of it,Google Patents might be a good place to get clues, if not actual answers, to your questions.

I think it's because the frequency difference is too large. The brain will just interpret them as two different sounds.

"Binaural beats are heard when the right ear listens to a slightly different tone than the left ear. Here, the tones do not interfere physically, but are summed by the brain in the olivary nucleus. This effect is related to the brain's ability to locate sounds in three dimensions."

"Consider the two waves starting in unison, f1 − f2 = 0. As the difference between f1 and f2 increases, the speed increases. Beyond a certain proximity (usu. about 15 Hz), beating becomes undetectable and a roughness is heard instead, after which the two pitches are perceived as separate. If the beating frequency rises to the point that the envelope becomes audible (usually, much more than 20 Hz), it is called a difference tone."

Both from http://en.wikipedia.org/wiki/Beat_(acoustics) which I linked to earlier.

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Mike

I had not seen that page before Mike, so thanks. Here's an excerpt from an link on that page.



The process of using external stimuli to match the characteristics of the brain functions, specifically the olivary nucleus and it's associated parts is interesting.

I went looking for Yhniwyata's question. 'multiple frequencies for binaural beats,'

I haven't found anything of useful to that, but my electronics training flags a reminder that the brains BB function at ~4 Hz is a serialized data flow and what comes from the external sources, as in the above scenario, is parallel.

Iv been experimenting with Omnipshere to make a bunch of different type of BB.
*4 hz beat with delay rate on it of 4 hz.
*4 hz beat with 4 hz different kinsd of LOD Oscolators
*4 hz with in Sine, Triangle, Square.
*4 hz with multiple base frequencies

I think a buch of frequencies in one ear would average out or have some mathmatical relationship of combining to a certen tone. then what ever diferece it has with the other side would entrain.


non of it seems to work as good as just a plain 4 hz beat.
Although i havent given it enough time to fully conclude that.

I am actually more concerend with finding was to slip in some BB to med music i make rather than finding some magical concocition, tho that would be cool.

Somethings along the line some music to start out behind ocean waves that makes you focus on a kinda swing pattern that is hard to follow to focus attention on rather than using a mantra. Then the complextivity of the music will fade out with just enough action in the right place to keep you from going unconscious untill it reaches a simple 4 hz BB that is subltle enough not to dystrac when actually in Point Conscousness mode.

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RBM, I did find some interesting info on the Google Patents website. Especially this one - Method of and Apparatus for Inducing Desired States of Consciousness which is credited to Monroe- http://www.google.com/patents?id=FQMiAA ... e&q&f=true

There are even schematics and diagrams at the top for the apparatus. (Is this simliar to some of the Monroe equipment Tom experimented with I wonder?)

Section 6 describes something called a Septon - "In this preferred embodiment, three binaural beat frequency signals are created between two audio carrier channels, and two amplitude beats per channel also are created, yielding a total of seven beat signals. The inventor has coined the term Septon for this set of beat signals."

It looks rather complicated. This example sure sounds like some of the Gateway CD tracks I have.

"A standard program according to this preferred embodiment would employ the following sound sequence:

0-5 minutes:
Signal Group A (comprised of replicated EEG waveforms having dominant values in the alpha range) Signal Group B (15 dB below Group A, generated simultaneously with the sounds of Group A, and comprised of replicated EEG waveforms having dominant values in the theta range)
Phased Pink Sound (six seconds, peak-to-peak, on both left and right channels, 20 dB below Group A)
Voice Inserts (repeated at 40 second intervals, 10 dB below Group A, simultaneously with the other sounds, and comprising short sequences of phrases like "relax" "let go", and "sleep")

5-20 minutes: Signal Group B
Signal Group C (20 dB below Group B, generated simultaneously with Group B, and comprised of replicated EEG waveforms having dominant values in the delta range)
Phased Pink Sound (15 dB below Group B, having aduration as in the first interval)
Voice Inserts (10 dB below Group B, comprised as above)

20-40 minutes: Signal Group C
Signal Group D (10 dB below Group C, generated simultaneously with Group C, and comprised of replicated EEG waveforms having dominant values in the lower delta range)
Phased Pink Sound (10 dB below Group C, having a duration as in the first interval)
Voice Inserts (20 dB below Group C, comprised as above)"

There is more to this sequence and tons of technical stuff in this paper.

I also found another site that talks about layering frequencies - http://www.immrama.org/brainwave/harmoniclayers.html. Note that I have not purchased nor listened to any of these CDs, but was more interested in the details of the technology.

For me, I think I am done looking into this topic further. There does appear to be something to the layering of frequencies that is beneficial to achieving certain states, but it appears to be too complex for me to figure out exactly how to mix them together myself. If it was crucial to anything of value, surely Tom would have hinted at mixing frequencies instead of just discussing the simple single ramp down to 4HZ. I will leave the mixing of frequencies to TMI, Jeffrey Thompson, and others who seem to do a much better job that I can do myself.

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Yhni

Glad to see you found Google Patents useful.

I've seen 'septon' mentioned somewhere but don't remember where.

By the way, which Gateway CD product do you have ?

I am about certain that in the third, or maybe fourth tape (now CD) of the first set of the Monroe gateway series, there is at least the theta beat going and, as one is "floating like a balloon, a 16-ish beats per second, almost clicking sound is introduced. My assumption was that this was to invirgorate, or activate, our normalish day-to-day rate of processing, making the experience rememberable.

Somewhere I recall reading someone's comment, or it might have even been Monroe's, on some early interview, of generating several different frequencies in the brain. Search out, if interested, Monroe's early interviews (Youtube.com)

-Montana

I have the entire TMI Gateway Experience on CD. If you turn the volume way up, you can definitely hear that there are multiple frequencies once the Focus X signal starts. I hear some very high frequencies mixed in with other lower frequencies. There are also panning effects that make part of the signal sound as if it is swirling around your head round and round.

These CD's put me into very interesting states even if I do occasionally zonk out. I was interested in the specifics of what I am listening to because the Gateway Experience tracks are not long enough. Even with the free flow Focus tracks (Focus 10, Focus 12, Focus 21 (what's the real difference!?)), by the time all the preparatory visualizations and relaxations are done there is only about 20 minutes time left to actually be in the state. I would like a nice long hour or so. :-)

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Yhni

Ha, only an hour ?

I've got 2 Hemi-sync CD's and a CD-recorded homemade posted here by someone loaded in my 6-CD player so I can extend even an hour.

Also, I have found the 'instantnap.gnaural' posted here, very helpful to play continuous as it's a function offered in the application.