Binaural beat refer to the auditory responses related to the
brain. binaural beat originate in the nucleus of each
cerebral hemisphere. When two different auditory impulses of
binaural beat, of two different frequencies interacts the
binaural beat are produced. Theoretically binaural beat can
be used to entrain specific neural rhythms and is possible
to utilize it as a technique for consciousness management to
entrain a specific cortical rhythm.
A German scientist, H. W. Dove, discovered binaural beat in
1839. The ability of a human being to hear binaural beat is
a result of evolutionary adaptation. binaural beat are due
to the brain structure of the human beings that they can
detect binaural beat. The frequencies at which binaural beat
can be detected depend upon the size of the species cranium.
Human beings, detect binaural beat if the carrier waves are
below 1000 Hz because at this frequency the wave length of
the signal is longer than the diameter of the human skull.
Binaural beat signals having frequency below 1000 Hz curve
around the skull by diffraction. The same effect can be
observed with radio wave propagation. As frequencies below
1000 Hz curve around the skull, both ears hear incoming
signals below 1000 Hz. But due to the distance between the
two ears, the brain "hears" the inputs from the ears as out
of phase with each other. As the sound wave passes around
the skull, each ear gets a different portion of the wave.
binaural beat are this waveform phase difference that allows
for accurate location of sounds below 1000 Hz. Audio
direction finding at higher frequencies is less accurate
than it is for frequencies below 1000 Hz. At 8000 Hz the
external ear becomes effective as an aid to localization.
Binaural beat works on the brain. When each ear hears two
different frequency signals, the brain detects phase
differences between these two signals. This detected phase
difference would provide directional information under
natural circumstances. When these phase differences are
heard, the brain processes the irregular information
differently and an integration of the two signals takes
place, producing another beat frequency. The difference
between the signals expands and collapses as the two
different input frequencies and get interlaced to result
constantly increasing and decreasing differences. This in
turn give rise to an amplitude-modulated standing wave
called the binaural beat. So the binaural beat are
fluctuating rhythm of the difference between the two
different frequency auditory inputs.
Binaural beat can be easily heard at low frequencies that
are below 30 Hz. binaural beat facilitates the entrainment
of brain waves and altered states of consciousness. The main
effect of listening to binaural beat is relaxing and
stimulating, depending on the frequency of the binaural-beat
stimulation. Binaural beat in the range of 1 to 4 Hz and 4
to 8 Hz are associated with relaxed, meditative, and
creative states and used as an aid to falling asleep.
binaural beat in the range of 8 to 12 Hz have increased
alpha brain waves and binaural beat in the range of 12 to 16
Hz are associated with reports of increased alertness and
Hearing the binaural beat passively may not spontaneously
propel human beings into an altered state of consciousness.
binaural beat stimulation is influenced by a number of
factors. For example, the willingness and ability of the
listener to relax and focus contributes to binaural beat
effectiveness in inducing state changes.
The binaural beat are related to an electro-encephalographic
(EEG) frequency-following response in the brain. The EEG
activity was termed as "frequency-following response"
because its period corresponds to the fundamental frequency
of the stimulus. binaural beat motivation appears to
encourage access to distorted states of consciousness.