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There has been a surge of interest in
binaural beats during recent years, and a number of software only
products that utilize this technology have become quite popular.
What are they?
A binaural beat is generated from two tones.
Each tone is of a slightly different pitch.
One tone is presented to the left ear, and the other to the right.
The two tones combine into a single tone sensed by your brain.
This single tone pulse is the stimulating when entraining with
binaural beats.
Binaural beats are probably the most well-known stimulus used for
entrainment. They have been shown to work, but other entrainment
techniques are more effective. Our machines produce binaural beats
and dual binaural beats. They also include other audio entrainment
methods in addition to these. I've personally found the that
frequency following effect of binaural beats is quite modest, but
they do actually work and have an effect on brainwaves that can be
shown with EEG.
Here's a bit of history from Gnaural's web page, which we'll
discuss in a moment.
In 1839, German experimenter Heinrich Wilhelm Dove discovered that
playing two tones simultaneously, one in each ear, induced the
perception of a "beat frequency" when the tones were of slightly
differing frequency (generally less than 100 Hz apart). What was
interesting about Dove's discovery was the fact that there was no
acoustic mixing of the tones. The perceived beats existed solely
within the auditory system.
Heinrich Wilhelm Dove
Heinrich Wilhelm Dove discovered binaural beats in 1839. While
research about them continued after that, the subject basically
remained a scientific curiosity until 134 years later, with the
publishing of Gerald Oster's article "Auditory Beats in the Brain"
(Scientific American, 1973). Oster's paper was landmark not so
much for its own new laboratory findings, but rather that in the
way in which it identified and tied together the isolated islands
of relevant research done since Dove, in a way that gave the
subject fresh insight and relevance to scientific research.
In particular, Oster saw binaural beats as
a powerful tool for cognitive and neurological research, addressing
questions such as how animals locate sounds in their
three-dimensional environment, and also the remarkable ability of
animals to pick-out and focus-on specific sounds in a sea of noise
(what is known as the "cocktail party effect").
Oster also considered binaural beats to be
a potentially useful medical diagnostic tool, not merely for
finding and assessing auditory impairments, but also (because they
involved different neurological pathways than ordinary auditory
processing) for more general neurological conditions. For example,
Oster found that a number of the subjects he worked with that were
incapable of perceiving binaural beats suffered from Parkinson's
disease. In one case, Oster was able to follow one such subject
through a week-long treatment of Parkinson's disease; at the
outset the patient couldn't perceive binaural beats, but by the
end of the week of treatment, the patient could hear them
again.
Oster also reported (in corroborating an
earlier study) that there were gender differences in the perception
of beats. Specifically, women seemed to experience two separate
peaks in their ability to perceive binaural beats that seemed to
correlate with specific points in the menstrual cycle (one at the
onset of menstruation, one around 15 days later), which led Oster
to wonder if binaural beats could be used as a tool for measuring
relative levels of estrogen.
Until Gerald Oster's 1973 article,
binaural beats were basically considered no more than a scientific
curiosity. Oster's paper was landmark not so much in presenting
new laboratory findings, but rather in identifying and
tying-together the isolated islands of relevant research done since
Dove in such a way as to give the subject fresh insight and
relevance to scientific research. In particular, Oster viewed
binaural beats as a tool for cognitive and neurological research,
addressing how we locate sounds in our environment, and the
so-called "cocktail party effect" (e.g., the auditory system's
propensity for selective attention). Oster also considered binaural
beats to have potential as a diagnostic tool, for finding
Parkinson's disease, auditory impairments, and even for gaging
fluctuations of estrogen (the latter assertion rising from a study
he replicated that corroborated findings of gender differences in
the perception of beats).
SBaGen is
a free binaural tone generator that has been out for quite some
time now. It works great, but there is a better out now called Gnaural2.
If you don't want to download and install Gnaural 2, you can use a
version placed on the web as a Java Applet. Check it out here
You can download Soundscapes and Gnaural Example files for Gnaural
here
You can even use them with the online Java Applet version.
A ton of links after the jump...
- The
cryosleep brainwave generator A free program to generate
brainwaves under Linux, demo sounds are online
- BrainWave Lab - Sound
Therapy
- Simple
summary chart of how Alpha, Beta, Delta, Theta & Gamma Waves
affect us
- SBaGen, a
free multi-platform program for binaural beats
- Gnaural, a free opensource
binaural beat graphical editor/generator for Windows and
Linux
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Gnaural Applet, a browser-based Java binaural beat
generator
- BrainJav,
a browser-based Java binaural beat generator
- bbEngine,
a freeware program for binaural beats for Mac OS X
- Brainwave
Entrainment to External Rhythmic Stimuli - Interdisciplinary
research and clinical perspectives symposium (Stanford
University)
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Auditory Driving - Overview of sonic entrainment methods
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Hearing Lecture Notes (5): Binaural hearing and
localization from University of Sussex
- Auditory
Illusions worksheet
from Rutgers University
- Brainwave/Cymatic Frequency
Listing
- The
Monroe Institute - originators of 'Hemi-sync' sound
system
- Centerpointe Research
Institute - originators of 'Holosync' sound system
- Immrama
Institute - step-by-step explanation of brainwave entrainment
and binaural beats
-
The Effect of Binaural Auditory Beats on the EEG of the Human
Brain — a student lab project from Penn
University
- (Heaven & Earth
Productions) The "Mental Alchemy" series -- outstanding 'real
time' geomantically-oriented binaural brainwave entrainment,
produced by Brendan Bombaci
- Downloadable
binaural beats in the public domain (various formats)
- Explanation of
binaural beats using examples
- free
binaural beat mp3's including 'the music of pi'
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