The Anatomy Of A Binaural Beat Soundscape Pt. 1

Now that we have gotten past some of the most basic forms of entrainment, I want to go over the anatomy of a basic tone containing a binaural beat.

This can be created using mostly any audio editor application. I've typically used Adobe Audition, but feel free to comb this list for other freeware alternatives :

http://open-tube.com/20-free-digital-audio-editors/


Before we go any further, it's time for the 'Standard Disclaimer/Warning' :

I would tread carefully in downloading any of these audio editors. Many of these sites use download mirrors like CNET and Softpedia, so it goes without saying to thoroughly virus-check anything you download before installing it.

Also - always make sure you are selecting the right 'Download' button. A lot of these sites have banner advertisements that try and trick you into thinking their 'Download' button is the real one.

(CNET in particular worries me - it always seems to set off the virus alerts built into the Firefox browser I'm using.)

Okay, now that I have told you everything you already know about the nature of the Internet, let's get back to the topic at hand :

So, let's say you want to make a sound file containing binaural beats to help you sleep. What should it contain?

The Audible Tones

Obviously, the most critical piece of the puzzle is the two audible tones that create the binaural beat. So let's say we want to aim for a binaural beat associated with 5 HZ (which would be associated with sleep). Like I had written in the previous entry, you're going to do two audible tones, one in each ear. The two audible tones should subtract out to 5 HZ.

How do we decide what exact audible tones to use? :

Pitch

While there is some debate over this, a common thought is that binaural beats will not work using audible tones over 1000 HZ. For that reason, you want to aim below that.

There is also a lower cutoff for the audible tones. You don't want to venture too far below 200 HZ with them.

There are a couple reasons for this -- for starters, the tones tend to get more bassy, and this is a mixed blessing for binaurals beats :

On one hand, if you want to smuggle the audible tones containing the binaural beats into music, what better place to hide them than in the bass range, since the human ear is less sensitive to that range?

On the other hand, does the lack of sensitivity humans have to the bass range make the binaurals less effective as a result? One would probably have to boost up the volume on the bass to compensate for this, which leads to the next potential issue.

When trying to incorporate binaural beats into music, generally the lower in audible tone you go, the more impact adding in the binaural is going to have on the perceived note, since there is less space [in HZ] between notes in lower octaves.

On top of all that, there is yet another reason why audible tones in the bass range can sometimes be bad for constructing binaurals, and it involves something we all hate -- math. (Okay everybody, get out your calculators.)

Given the two audible tones you are using to construct a binaural. Take the lesser of those two numbers and multiply that by 16%. That value is the maximum binaural beat that can be created by these audible tones.

For example, say you wanted to use audible tones around 100 HZ to create a binaural. The maximum binaural value that could be supported would be 100 HZ x 16 %, or 16 HZ.

As you can see -- a 200 HZ tone is going to be able to cover most of the gamut of brainwave frequency ranges. (It would be able to accommodate binaurals up 32 HZ, and more often than not, that's as high as you'll need to go.)

Once you start going below 200 HZ (and particularly below 100 HZ), you're starting to limit the binaural beat playing field a little.

Waveform

I believe it has been said that the triangle waveform is best to use for the audible tones comprising binaurals. (I can't remember the exact reason why.) I find I usually stick with sine waves or triangle waves, and use square and sawtooth waves less frequently.


Volume [Amplitude]

I'm calling it volume, even though amplitude is probably the more accurate name. The volume of the audible tones should be comfortable to listen to. Generally, the higher up you go towards 1000 HZ, the less overall volume you need for the tone, since the ear gets more sensitive to sound as you head up that way. If you're using a background sound, it's perfectly okay to let the background sound take the lead volume-wise, while putting the audible tones containing the binaural a bit further in the background.


Panning

I wouldn't do any panning with the audible tones containing the binaural. The short answer is it will probably mess with the binaural functioning.

The long answer is there are probably ways you can incorporate panning into the audible tones that comprise the binaural beat, but it's not an exact science. If you were to have the left and right channels trade places X times a second, at slower panning speeds I'm thinking you'd get something that alternated between a binaural and monaural. At faster panning speeds, you would end up with a monaural, I would think - since the brain would effectively perceive both tones as being in both ears. The more I think about this, the more I want to experiment with this -- the frequency of the panning between the left and right ear itself would have a brainwave entrainment effect itself. It would be interesting to see how the brainwave entrainment effect caused by the binaural interacted with the brainwave entrainment created by the panning itself. If the binaural beat was 7 HZ and the frequency
of the panning was 6 HZ, you might end up with an almost polyrhythmic sort of effect.

Sample Rate

This is getting a little more technical.

Just to give a definition of Sample Rate from WhatIs.Com :

"In developing an audio sound for computers or telecommunication, the sample rate is the number of samples of a sound that are taken per second to represent the event digitally."

Now, it's time for math :

The sample rate of the audio file needs to be at least twice as much as the highest frequency you wish to hear in the sound. For instance, if you want to hear frequencies in a sound in the 4000 HZ range, you're going to need at least an 8000 HZ sample rate.

On the other side of the coin, generally the bigger the sample rate is, the bigger the file size will be.

For binaural beats, since the audible tones comprising the beats will be under 1000 HZ, you should be able to save the file with an extremely small sample rate, which results in a very small file size. I have tested binaurals I've created with sample rates as low as 6000 HZ, and have still been able to perceive the brainwave entrainment effect. (Just to put the 6000 HZ sample rate in perspective, audio from a music CD typically has a 44100 sample rate, and DVD audio can be even higher than that.)

Now, the downside of using low sample rates with binaural beats :

• If you're using more elaborate waveforms with harmonic overtones, you may end up cutting out some of those overtones.

• You're generally not going to create a binaural beat in a vacuum, because naked binaural tones are boring. People need something acoustic to chew on, so you typically will add a background sound of some kind (ocean waves, noise, etc). These sounds will have higher frequencies, and will warrant a higher sample rate. 

This actually serves as a good lead-in to the next section, dealing with background sounds, and how they make the binaurals less monotonous. (If binaural beats are the pill, the background sound is the yogurt you hide it in to make it palatable.)

That will be 'Pt 2', since I'm getting carpal tunnel here. If I do any more typing tonight, I think my fingers will unionize and go on strike. (Although, a horde of striking finger puppets is admittedly an entertaining thought.)

Brainwave Entrainment : Some basic types

I'm going to go over some of the more common methods/sources of brainwave entrainment here. This list isn't exhaustive. I'm really just scratching the surface.

I welcome any feedback you may want to offer - I don't know everything, so if you think I am botching up some detail below, feel free to call me on it in the comments section.

Additionally, if you think there are better ways for me to present this information, let me know. 


I Visual Entrainment :

Lights flickering X times per second can be used to entrain in the brain into various mental states. Point in case - a strobe light flashing 20 times a second can be used to energize a crowd of people.

A variation on this theme - if one watches something moving/oscillating X times a second, this can also potentially be used to entrain the brain. (Example : A hypnotist swinging a timepiece or some other object on a chain to put somebody into a trance.)

II Motion Entrainment : 
 
Any periodic motion a person experiences can also have brainwave entrainment effects.

Examples : A rocking chair, swinging on a swing, a mother gentling rocking a child in her hands, etc.

III  Electromagnetic Entrainment

Electromagnetic fields generated by appliances, power lines and other sources can also potentially entrain the brain. It's one of the reasons why some sources will advise against sleeping with an alarm clock too close to your head. (The EM field of an alarm clock is much higher than the delta and theta ranges associated with sleep - it's thought for that reason that the alarm clock can interfere with sleep.)


There are also 'geomagnetic' fields created naturally which can entrain the brain just as an artificial EM field can.

IV Felt Entrainment 

I was debating whether to include this category, but I think it's worth mentioning (since really bridges the gap to audio below). Any felt stimuli can potentially have brainwave entrainment effects. Think a device that generates vibrations, or somebody doling out a massage. Also, a recurring beat/rhythm  from subwoofers - instances where it's more 'felt' than heard.


V Audio Entrainment

For me, this is the main category that I devote most of my time to playing with (although I do like to do visual entrainment also with strobe lights.)

Any repeating\recurring\periodic sound-based stimuli can potentially entrain the brain. This can be done by changing up any number of qualities about the sound :

* Volume - the sound fades in and out X times a second. (This is the classic 'gapper' effect sometimes heard in electronic music, and you may here it referred to as 'isochronic tones'.)

* Pitch - the pitch of the tone goes up and down X times a second.

* Panning - Using headphones, the tone cycles between the left and right ear X times a second.

This is just scratching the surface - literally any characteristic of the sound, if changed up X times a second, can potentially entrain the brain. Other characteristics that can be modulated -- the EQ, the tone color (timbre), the waveform (sinus, sawtooth, triangle, etc), and the phase between the left and right channels.

(Side Note : Cool Edit's 'Brainwave Synchronizer' feature made use of phase modulation. Cool Edit was ultimately acquired by Adobe, and became Adobe Audition -- the Brainwave Synchronizer effect was named the 'Binaural Auto-Panner'. I believe it still makes use of phase modulation.)

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One other method of audio entrainment involves binaural beats and monaural beats.

Before we go any further, I want to make sure to distinguish between binaural beats and binaural recording, which are two different animals.

Binaural recording is a method of recording sound intended to create a realistic 3D environment. This is often with a microphone shaped like a human head, so it captures sound exactly as a human head would.

Now, with that out of the way, let's get into binaural and monaural beats :

* Binaural beats : This is a method of brainwave entrainment listened to through headphones. To generate an entrainment frequency, two audible tones are used, one in each ear. The difference between the two tones should subtract out to the intended entrainment frequency.

For example, if you want to entrain to 5 HZ (which would be used to promote sleep), you could do this by putting a 200 HZ tone in the left ear, and a 205 HZ tone in the right ear. The brain is going to try and reconcile the subtle difference between the two tones in each ear -- it will end up hearing a single tone, but it will also hear a series of beats - five beats a second. These 'beats' can entrain the brain.

One thing to note - if you play the audio through speakers instead of headphones, you'll end up getting monaural beats instead of binaural beats (see below). [There is an exception to this, but I don't want to over-complicate things - yet.]

* Monaural beats : Monaural are very similar to binaural beats, except instead of having the two tones separated between the left and right ears, you just overlap the two tones period. So, using the example above, you would layer a 200 HZ tone over 205 HZ tone. The end result can be played through standard speakers - headphones are not necessary. Where as binaural beats are formed by the brain trying to reconcile the difference in tones between the left and right ears, monaural beats are the result of the tones mixing in open air after coming out of the speakers.

Brainwave Frequency Ranges : The Big Five (Delta/Theta/Alpha/Beta/Gamma)

When it comes to Brainwave Entrainment, I guess the best place to start is at the beginning.

I had mentioned in a previous post that there are different 'ranges' of brainwaves generated by the brain, corresponding with different mental states.

These are the most common brainwave frequency ranges you'll encounter :

Delta Range (under 4 HZ) : Associated with deep sleep.

Theta Range (4 HZ to 8 HZ) : Associated with dreaming sleep.

Alpha Range (8 HZ to 13 HZ) : Associated with awake but relaxed states.

Beta Range (14 HZ to 35 HZ) : Associated with wide awake states. (Things head into the land of hyper vigilance as you reach the higher end of this range.)

Gamma Range (35 HZ to 45 HZ) : The borders of this range are kind of ill-defined. The center is generally thought to be around 40 HZ. This frequency range is associated with consciousness. When somebody is put under general anesthesia, brainwaves in the gamma range typically disappear.

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While I could oversimplify and say that your brain is 'tuned' to a certain brainwave frequency at any point in time, that's not entirely accurate. There are brainwaves in all the different ranges simultaneously happening - the ratio of these brainwaves is what changes over time. (For instance, when you're in deep sleep, the most dominant brainwave frequencies are in the delta range.)

Another thing to point out is that there's a lot of variation as to where different sources say the various brainwave frequency ranges begin and end. It seems like there is more agreement for the Delta and Theta ranges, but once you start to get to the upper limit of the Alpha range, that's where there's more disagreement.

You may also see some other brainwave frequency ranges get thrown into the mix (Epsilon/Lambda), but I'm leaving them out of the equation for now. (They're not as commonly used.)

Resurrecting The Acoustic Phoenix

This is going to be an attempt to bring back the old Sonic Alchemy Logbook that I used to produce on the Papercut Suicide website about 15 years ago :

http://lunarsight.com


A little about the website :

That website evolved out of a Geocities site I created in 1996, and it certainly looks its age. I think any modern web developer would probably have an aneurysm reading the HTML code that went into that page. It's equal parts Netscape Navigator and Microsoft FrontPage, and it's a testament to the backwards compatibility of the internet that the page still works at all. (Not only does it still work, but it shockingly looks pretty good from mobile devices -- I'm not sure how the heck that happened.)

Now that I've given the back history of the main website, I'll go on the record and indicate probably nobody cares about most of the website. Like many websites from the early internet, it was primarily a place to post poetry, art, animated gifs, and random links to random things.

However, it seems that one subset of pages did and still do get a lot of attention. That being the Brainwave/Cymatic Frequency List :

http://lunarsight.com/freq.htm

Brainwave Entrainment :

In the late 90s / early 00's, I was heavily interested in computer-generated music and sounds. Early on, I used a sound editor called CoolEdit for much of my early experimentation. One feature of CoolEdit was a way to create sounds that entrained the brain to certain mental states.


I'll get more into this later, but to quickly summarize brainwave entrainment now, it's a method of using sound, light (and other stimuli) to coax the brain into various mental states (wide awake, asleep, etc).


Let me provide a simple visual example - A strobe light. 

If a strobe light is flickering 15 times a second, the brain is going to try and replicate this rate with its own brainwaves. (The brain plays monkey-see/monkey do with the stimuli.)

Now, different brainwave rates are associated with different mental states.

Basically, slower brainwaves (under 7 HZ) are associated with sleep. Higher brainwaves (8 HZ and above) are associated with being awake. Generally, the higher up you go, the more wide awake you are. So, 10 HZ would be awake but fairly relaxed. Whereas at 20 HZ and higher, you're playing some intense fighting video game, and are putting every ounce of concentration into not getting your butt kicked by the other guy. [Read : You're as wide awake as wide awake can possibly be.]

Back To The Frequency List :

As I got deeper into experimenting with sound, I began to play with other sound-based applications. I was big on fractal music generators for a while, and when I was doing more monotonous data entry work, I often would have the fractal music playing indefinitely, to keep my brain occupied.

I also began to use an application called Brainwave Generator, which like Cool Edit, had a method of creating sounds to entrain the brain. (I'll come back to all the brainwave entrainment methods in a later post. There are all manner of different ways to do it, and the individual methods don't exist in a vacuum either. You can mix and match them together.)

Anyway -- I began to find all manner of different websites online indicating different frequencies associated with different things. The nature of the frequencies weren't just limited to brainwave entrainment. They covered ground associated with other 'sound healing' methods [chakras, for instance]. Also, some of the frequencies weren't associated with sound at all. [Rife Frequencies were presumably used for healing, but the healing was doled out via machines that produced 'energy'.]

I began to compile a list of all the frequencies I came across.

The list was originally intended for my own personal experimentation. I was heavily dabbling in electronic music at the time, and the frequency list served as a 'sound dictionary' for me. For instance, if I wanted to represent the planet Mars in a track, what better way to do it than use a sound frequency that was calculated right from the revolution/rotation of the planet? (That really appealed to my inner geek.)

I ultimately decided to post the frequency list online, figuring there may be some other people out there who would find some use in it (or at least get a laugh out of it).

Again, this was when the internet was still young, and people were more interested in just sharing information rather than making a profit off everything.

The Sonic Alchemy Logbook

For a while, I was posting my sonic experimentation to a separate page on Papercut Suicide. It can be found here :

http://lunarsight.com/son-alc.htm

I also included samples of the sonic experimentation for other people to download. Brainwave Generator presets were my preferred method of posting the samples, since the preset files were usually pretty small. I sometimes would also post WAV files for limited periods of time (although file size was often a problem - there was limited storage back then).

Ultimately, I stopped updating the logbook, since I was going into the HTML each time I wanted to add an entry, and it was a pain in the neck.

Blog-GING? Can I HAS Blog-GING?

I had been considering bringing back the Sonic Alchemy Logbook for years.

I kept on hearing about this 'blog' thing, which supposedly made it super easy to post information without even having to code anything in HTML. (What manner of sorcery is this??)

I began searching for a blogging site to use, only to find out I already had one. (Apparently the multi-headed Hydra that is Google had Blogger as part of its lists of services.)

So, here I am -- hopefully I can maintain this blog over time (provided there are no lapses in my attention span, which is typically pretty good as long as I steer clear of butterflies and other small distracting mammals -- like squirrels, who I think were put on this earth simply to distract humans with their silly antics.)

Mike / Papercut Suicide