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What is Gnaural?

Gnaural is an opensource programmable auditory binaural-beat generator, implementing the principle described in the October 1973 Scientific American article "Auditory Beats in the Brain" by Gerald Oster. The theme of the article is that the processing of binaural beats involves different neural pathways than conventional hearing. Research inspired by the article went on to show that binaural beats can induce a "frequency-following response" (FFR) in brainwave activity. An early version of Gnaural called WinAural was used for at least one such 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.

My personal interest in binaural beats has centered almost exclusively around the FFR potential of binaural beats, in order to facilitate meditation. But Gnaural was designed to be neutral with regard to any application or hypothesis, relying strictly on the basic principle as described in Oster's overview.


Want to try it out before installing?

Click on the picture to the right to try a simplified (no editing capabilities, basically) version of Gnaural I wrote for your web browser. To run it, you'll need to have Java installed.


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 solely 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.

Oster viewed binaural beats as having value both for pure research and a diagnostic medical tool. In terms of research, he felt they could be used to explain features of our auditory system, including how we locate sounds spatially in our environment and selectively single-out individual sounds from background noise (see "cocktail party effect"). Medically, Oster saw potential in BBs not only to directly diagnose auditory impairments, but to identify surprising range of seemingly unrelated medical issues. For example, Oster found strong data that diminished ability to hear binaural beats was an early predictor for Parkinson's Disease. He also found that variation in the ability to perceive binaural beats correlated subtly with where individuals were in hormonal cycles. Central to his thesis that binaural beats involved different neural pathways than conventional hearing was the fact that binaural beats evoke neural responses even when both tone frequencies are below the human hearing threshold.

Do binaural beats influence brainwave activity?


Many consider the idea of binaural beats influencing brainwave activity "controversial", but only the claims of what the influence means are controversial. That rhythmic stimuli can induce FFR is well established across many species, comprising a subject known as "driving", with binaural beats falling under the category "auditory driving", but not having a monopoly on it. Even the isochronal beating of a drum can induce FFR. But binaural beats appear to have advantages over other auditory approaches by being more efficient, both as a true low-frequency sinusoidal stimulus and by engaging more neural circuits than conventional hearing. BBs are also less invasive than some of the non-auditory approaches such as photic or electromagnetic, which are effective but induce seizures in a percentage of the population. In my experience, binaural beats have been as harmless as anything else I listen to through headphones.

I also embrace the fact that binaural beats require a conscious effort to get their effect, since i am not interested in replacing meditation but in facilitating it, particularly when anxiety or stress have made it hard to start meditating in the conventional way.

As for "snake-oil" claims by profiteers as to what binaural beats can do (ranging from targetting specific drug states to curing disease), my experience is that low frequency brainwave entrainment works as a blanket effect, to create a focused mental state similar to hypnosis, in which heightended suggestibility causes the individual's expecations to strongly influence their experience. But rather than take a dim view of this, I consider it a positive: binaural beats are a powerful tool for implementing suggestion and facilitating the exploration of mental states. And in regard to those who equate "suggestibility" with "gulibility", even the AMA now acknowledges that placebo, despite having no scientifically understood mechanism and raising ethical issues of doctor-patient trust, nevertheless gives a significant and statistically reliable effect positively impacting a percentage of people for whom conventional treatment has failed or is not available.

The power of placebo alone to effect cures not achievable through medical means is enough to suggest that intent, expectation, belief, and suggestibility are among the mind's most powerful features. And as a means of tapping in to that power, I've found binaural beats to be an effective tool. And in that philosophy, I believe that the most important ingredient of a binaural beat session is intent. Rather than seeing specific frequencies as effecting specific results, I see any schedule facilitating a suggestible-state as having the potential to result in a wide range of outcomes, dependent on what one intends to experience. For example, given one solid entrainment schedule, one can choose to embark on an exploration of anything from meditation to "OBE's", or help solve problems ranging from addiction to insomnia. The crucial ingredient in intent.

I will also add that because of the voluntary nature of the process, I have never experienced any "addictiveness" with binaural beats; in fact, my experience has been the opposite: the familiarity the approach has afforded with changing brainwave activity has made it easier 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.