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Gnaural 1&2

What is Gnaural?

Gnaural is a multi-platform programmable binaural-beat generator, implementing the principle of binaural beats as described in the October 1973 Scientific American article "Auditory Beats in the Brain" (Gerald Oster). There has been considerable research done on the subject since that publication, and WinAural (an early version in the Gnaural lineage) was used as the audio stimulus for at least one published study, "The Induced Rhythmic Oscillations of Neural Activity in the Human Brain", D. Cvetkovic, D. Djuwari, I. Cosic (Australia), from Proceeding (417) Biomedical Engineering - 2004.

The central theme of Oster's article is that processesing of auditory binaural beats bears distinct differences from that done for normal sound, emphasizing different neural pathways and highlighting different parameters of the sound stimulus.

Oster's observations inspired a wave of research in to the ways in which binaural beats could affect the brain. One area of research explored how binaural beats could evoke a "frequency-following response" (also known as "brainwave entrainment") in EEG measures. My personal interest in binaural beats has centered almost exclusively around exploring this entrainment potential as a means of facilitating meditative states. However, Gnaural was designed to be neutral with regard to any hypothesis or application, relying strictly on the fundamental findings as described in Oster's 1973 overview.

What are auditory binaural beats?

In 1839, German experimenter Heinrich Wilhelm Dove discovered that illusory "beats" are perceived when pure tones of slightly different frequency are separately and simultaneously presented to each ear. Dove's insight was to realize that since there is no acoustic mixing of the tones, the perceived beats must exist soley within the auditory system, specifically that part which processes binaural (e.g., "stereo") sound.

While research in to binaural beats continued after that, the subject was viewed largely as no more than a scientific curiosity. Oster's paper was landmark not so much for its laboratory findings, but in how it tied-together the isolated islands of research since Dove in a way that gave the subject a renewed relevance to modern scientific questions.

In particular, Oster viewed binaural beats as a tool with both research and medical application. In terms of research, he felt it could be used to explore the neural pathways involved in auditory cognition, and also to address higher-level questions such as how we locate sounds spatially in our environment and how we can selectively pick-out individual sounds from a sea of noise (see "cocktail party effect").

Medically, Oster saw potential for binaural beats as a diagnostic tool, both for auditory impairments, and for a surprsing range of non-auditory subjects. Of the latter, most notable was his observation that a diminished ability to perceive binaural beats preceeded the onset of Parkinson's disease. He also presented data corroborating findings that the ability to perceive binaural beats is influenced by hormonal levels.

Notable for Oster's thesis was the fact that binaural beats are perceived even when one of the two frequencies is below the human frequency threshold, and also when both frequencies are below the human volume threshold. This, combined with the brain data available at that time, suggested to Oster that the processing of binaural beats followed different neural pathways in the brain from other auditory processing.

Do binaural beats influence brainwave activity?

The publication of "Auditory Beats in the Brain" launched a new wave of research in to binaural beats. The avenue that caught my attention was the "frequency-following response" (FFR), in which features of a brain EEG could be influenced to "lock-on" to the beat frequency of a binaural auditory stimulus. The effect suggested to me a means of inducing states like meditation and sleep.

The overall subject of influencing brainwave activity with rhythmic stimulus is known as "driving", and while binaural beats have no monopoly on driving, they have some distinct advantages over other approaches. For one, binaural beats lack the negatives of the more invasive approaches, which in the case of photoic and electromagnetic stimuli include a risk of seizures. In my experience, binaural beats are as harmless as anything else I listen to through headphones.

I've found that the most important ingredient of a binaural beat session is one's intent. As in, the same theta range schedule can have the effect of facilitating deep meditative, sleep, or even extraordinary alternative states of consciousness, depending on one's focus.  Because of the voluntary nature of the process, I have never seen any inclination toward addictiveness. In fact, I've found that the familiarity with voluntarily slowing brainwave activity has made it easier for me to both sleep and meditate without them.

These strictly represent my thoughts and observations, however, and I make no guarantees about what the technique can or can't do for anyone else. Some of the more unusual applications I've heard about with the Gnaural lineage include sustaining a heightened mental focus for online tournament gaming, and enhancing flotation-tank and related sensory deprivation environments. Many people also apparently use the technique to study more effectively.

Gnaural's History?

Gnaural has had a very long lineage, starting with a DOS program in the mid 1990s, progressing to WinAural for Windows, then BrainJav for Java [NOTE: see GnauralJavaApplet for the latest Java version], and finally the truly cross-platform Gnaural solution. In over a decade of experience with the technique, I have found mainly  useful in areas of sleep induction and "power napping", and also as a way to bring meditation both within reach (when stress has put it out of reach) and to extend its boundaries over time.

More on binaural beats?

Binaural beats have the unusual property of being able to deliver direct auditory stimuli at sub-audible frequencies (below the range of human hearing), by virtue of heterodyning being simulated within the auditory system.  

The reason this is interesting in regard to FFR is that (generally speaking) the spectrum of perceivable acoustic frequencies is well above the frequency spectrum of brainwave activity. Thus, aside from binaural beats, the only means of presenting acoustic driving stimuli is by externally modulating sound (in to waves or pulses whose periodicity falls within the spectrum of brainwave frequencies).

Binaural beats, on the other hand, provide a direct means by which pure acoustic tones can be delivered to directly produce a driving stimulus within the range of brainwave activity. Perhaps even more important (in regard to driving) is that with binaural beats, the driving stimulus arises internally (within the auditory system). This suggests that binaural beats may more effectively induce driving than simple monaural modulation, if only for the fact that the resulting stimuli arises directly within neural pathways that can be measured in the course of gauging brainwave activity.

Is Gnaural free?

Yes, in the sense that it is Open Source and released under the GNU General Public License. It was written with the very popular multi-platform GTK+ libraries (core to tens of thousands of applications and even the entire Gnome desktop) with the intention of making it portable to all platforms. Currently GTK+ works for Linux, Windows, and finally also Mac (thanks to the GTK+ libraries finally getting ported).