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Patent No. 5159703 Silent subliminal presentation system (Lowery, Oct 27, 1992)
Abstract
A silent communications system in which nonaural carriers, in the very low or very high audio frequency range or in the adjacent ultrasonic frequency spectrum, are amplitude or frequency modulated with the desired intelligence and propagated acoustically or vibrationally, for inducement into the brain, typically through the use of loudspeakers, earphones or piezoelectric transducers. The modulated carriers may be transmitted directly in real time or may be conveniently recorded and stored on mechanical, magnetic or optical media for delayed or repeated transmission to the listener.
Notes:
Silent
subliminal presentation system. Filed December 1989, granted October 1992. Brain
programmer with or without entrainment. States that it can be used when other
sounds are present. Shows how to detect it. Can be stopped by use of earplugs
that stop frequencies used from entering ear. Also this would show up on EEGs
as evoked potentials even being subliminal.
BACKGROUND--FIELD
OF THE INVENTION
This invention relates in general to electronic audio signal processing and,
in particular, to subliminal presentation techniques.
BACKGROUND--DESCRIPTION OF PRIOR ART
Subliminal learning enjoys wide use today and subliminal tapes are being manufactured
by a number of companies in the United States alone. Several decades of scientific
study indicate that subliminal messages can influence a human's attitudes and
behavior. Subliminal, in these discussions, can be defined as "below the threshold
of audibility to the conscious mind." To be effective however, the subliminally
transmitted information (called affirmations by those in the profession) must
be presented to the listener's ear in such a fashion that they can be perceived
and "decoded" by the listener's subconscious mind. We are referring to audio
information in this discussion, however, information could be inputted into
the subject's subconscious mind through any of the body's sensors, such as touch,
smell, sight or hearing. As an example, early development work in the subliminal
field utilized motion pictures and slide projections as the medium. Early research
into visual and auditory subliminal stimulation effects is exemplified by U.S.
Pat. Nos. 3,060,795 of Corrigan, et al. and 3,278,676 of Becker. U.S. Pat. No.
4,395,600 of Lundy and Tyler is representative of later developments in today's
subliminal message techniques.
The majority of the audio subliminal tapes available today are prepared using
one basic technique. That is, the verbal affirmations are mixed with, and recorded
at a lower level than, a "foreground" of music or sounds of ocean surf or a
bubbling mountain brook or other similar "masking" sounds. The affirmations
are generally recorded 5 decibels (db) or so below the "foreground" programming
and regenerative automatic gain control is usually applied to permit the affirmations
to change their recorded amplitude in direct proportion to the short term averaged
amplitude of the continually varying "foreground" material. In other words,
the volume of the affirmations will follow or track the volume changes of the
"foreground" programming, but at a lower volume level. Circuit provisions are
also usually included to "gate" the affirmations off when the music amplitude
is low or zero. This insures that the affirmations cannot be heard during quiet
program periods. Thus, today's subliminal affirmations can be characterized
as being "masked" by music or other sounds, of constantly changing amplitude
and of being reduced or cut off entirely during periods of low or quiet "foreground"
programming.
One of the principal, and most widely objected to, deficiencies in available
subliminal tape presentation techniques is that the presence of the "foreground"
material is intrusive to both the listener and to anyone else in the immediate
area. No matter what "foreground" material is chosen, the fact remains that
this material can be heard by anyone within its range and presents a definite
distraction to other activities such as conversation, thought, desire to listen
to other programming such as radio or television, need to concentrate, etc.
Additionally, and because the tapes are used repeatedly by the same listener,
any "foreground" music or material eventually becomes monotonously tiring to
that listener.
It is the purpose of the following described invention to eliminate or greatly
reduce all of the above deficiencies. Although its application to the magnetic
tape medium is described in the following discussion, the technique is equally
applicable to most other desired transmission mediums, such as Compact Disc,
videocassettes, digital tape recorders, Public Address (PA) systems, background
music installations, computer software programs, random access memory (RAM),
read only memory (ROM), "live", real time applications and other mediums now
in existence or to be developed in the future.
Implemented on tape cassettes, for example, the subliminal presentation described
here is inaudible i.e., high audio or ultrasonic frequencies, the affirmations
are presented at a constant, high amplitude level, and they occupy their own
"clear channel", non-masked frequency allocations. If desired, the previously
described "foreground" music or other material can be added to the tape through
use of an audio mixer. The "silent" recordings are inaudible to the user or
by others present and are therefore very effective for use during periods of
sleep or when in the presence of others. Additionally, the basic requirements
of subliminal stimulation are met. That is, the affirmations are efficiently
transmitted to the ear and, while undetected by the conscious mind, are perceived
by and efficiently decoded by the subconscious mind.
OBJECTS OF THE INVENTION
Accordingly, several objects and advantages of my invention are:
(a) to provide a technique for producing a subliminal presentation which is
inaudible to the listeners(s), yet is perceived and demodulated (decoded) by
the ear for use by the subconscious mind.
(b) to provide a technique for transmitting inaudible subliminal information
to the listener(s) at a constant, high level of signal strength and on a clear
band of frequencies.
(c) to provide a technique for producing inaudible subliminal presentations
to which music or other "foreground" programming may be added, if desired.
Still further objects and advantages will become apparent from a consideration
of the ensuing description and drawings.
BRIEF
DESCRIPTION OF THE DRAWINGS
In the drawings, the first digit of each component number also refers to the
figure number where that component can be located.
FIG. 1 represents the block diagram of a suitable system which will generate
a frequency modulated (FM) signal at 14,500 Hz.
FIG. 2 represents an approximation of the frequency response curve of the human
ear and the signal decoding process.
FIG. 3 represents the block diagram of a suitable system which will generate
a single sideband, suppressed carrier, amplitude modulated (AM) signal at 14,500
Hz.
______________________________________ REFERENCE NUMERALS IN DRAWINGS ______________________________________
11 microphone or other 14 low distortion audio input signal audio oscillator
12 audio preamplifier 15 high pass or band if required pass audio filter 13
frequency modulation 16 output to tape circuit recorder or other device 21 point
on low freq end 25 midpoint on curve response curve between points 23 and 24
22 point on low freq end 26 speaker output of FIG. 1 to of ear response curve
ear 23 point on high freq end 27 demodulated subliminal of ear response curve
audio inputted to ear 24 point on high freq end 31 microphone of ear response
curve 32 speech amplifier 33 balanced modulator 34 carrier oscillator 35 filter
(455 KHz) 36 mixer 37 heterodyne oscillator (469.5 KHz) 38 bandpass filter 39
output signal ______________________________________
DETAILED DESCRIPTION OF A PREFERRED
EMBODIMENT
Please refer now to FIG. 1 and FIG. 2, which are drawings of a preferred implementation
of the invention.
The principle of operation of the silent subliminal presentation system is as
follows:
An audio signal in the upper frequency region of the audio spectrum (for example,
14,500 Hz) is modulated with the desired information. The type of modulation
may be any type suitable for subliminal applications; frequency modulation (FM),
phase modulation (PM), upper single sideband with suppressed carrier, amplitude
modulation (AM), tone modulation, etc.
For broadest application, the high audio frequency selected as the carrier frequency
must meet two basic criteria:
(1) be high enough in the audio spectrum that its presence to the human ear
is essentially unnoticed or undetectable (without the listener being informed
that the signal is actually present) and,
(2) be low enough in the audio spectrum that it (and its modulation content)
can produce a useful output power from home entertainment type cassette or reel-to-reel
magnetic recorders.
This would also include, of course, small portable and automobile tape decks.
Alternatively, the output of the system can be fed directly into an audio amplifier
and its speaker/earphone system, Public Address system, etc.
FIG. 1 provides the block diagram of an example of a system capable of generating
the desired silent frequency modulated carrier.
The modulation information is inputted into the microphone 11. Other suitable
input devices may be substituted for microphone 11, such as a tape recorder
or a radio. The microphone 11 is connected to the preamplifier 12 and should
have provisions for adjusting its gain in order that the optimum modulation
index can be set in the frequency modulator 13. The frequency modulator 13 modulates
the frequency of oscillator 14 which has been adjusted for an output of 14,500
Hz as described above. The output of oscillator 14 is fed through a suitable
bandpass filter 15 into the tape recorder or directly into a suitable amplifier/speaker
system. It is the purpose of the bandpass filter to remove or attenuate audible
products of the modulation process in order to maintain as audibly silent an
output as practical.
On the receiving end, FIG. 2 represents an approximate and idealized frequency
response curve of the human ear. The frequency modulated carrier (centered at
14,500 Hz), as generated above and played through a tape recorder or amplifier/speaker
system, is shown on FIG. 2 as speaker output 26, impinging upon the upper slope
of the ear's response curve at point 25. The frequency modulated excursions
of the speaker output 26 swing between points 23 and 24 on the ear's upper response
curve. Because the response curve between points 23 and 25 is relatively linear,
this action results in a relatively linear demodulation of the original modulation
intelligence, which is passed on subliminally to the inner ear. The amplitude
of the demodulated output is not high enough to be detected by the conscious
mind but is sufficient in amplitude to be detected by the subconscious mind.
In the field of communications engineering design, the above demodulation process
in known as slope detection and was used in early FM receiver design. In those
receivers, the response curve was formed by the action of a tuned (inductive/capacitance)
circuit. In our case, the response curve is formed by the natural response curve
of the human ear. The same slope detection technique can be performed at the
low frequency end of the human ear response curve. This region is indicated
on FIG. 2 as between points 21 and 22. This region, however, has a much smaller
available bandwidth and is therefore more restricted as to the amount of information
that can be transmitted in an inaudible manner.
In practice, the listener adjusts the volume control of the tape recorder or
amplifier to a level just below that at which the listener hears an audible
sound or noise from the speaker of the tape recorder. If the recording process
is properly done, a spectrum analyzer or a calibrated sound level meter will
reveal a strong signal emanating from the tape recorder speaker. A calibrated
sound level meter, at a distance of 1 meter (with C weighting and referenced
to the standard of 0.0002 micro bar) will typically indicate a silent power
output of from 60 to 70 decibels. This is equivalent to the audio power of a
loud conversation, yet, in the described system, is inaudible or unnoticed by
the listener.
FIG. 3 illustrates a system which generates a suitable amplitude modulated (AM)
signal, instead of the frequency modulated (FM) system described above. The
output is a modulated, single sideband (SSB), suppressed carrier (AM) signal
at 14,500 Hz.
The block diagram represents a common scheme for generating an SSB signal and
will be briefly described.
The desired subliminal information is spoken into microphone 31. This signal
is amplified by speech amplifier 32 and injected into one port of balanced modulator
33. A continuous wave signal of 455 KHz is generated by carrier oscillator 34
and is injected into the second port of balanced modulator 33. The output of
balanced modulator 33 is a double sideband, suppressed carrier signal at 455
KHz. This signal is fed through filter 35, causing one of the two sidebands
to be removed. This signal is fed into one port of mixer 36. A continuous wave
signal at a frequency of 469.5 KHz from hetrodyne oscillator 37 is fed into
the other port of mixer 36, resulting in an output of the original subliminal
audio information but translated 14,500 Hz higher in frequency. The bandpass
filter 38 attenuates signals and noise outside of the frequencies of interest.
The amplitude modulated audio output signal is shown as output 39.
Thus, as stated earlier, my invention provides a new system for subliminal presentations
which is:
(a) silent,
(b) outputs a constant, high level modulated signal and,
(c) occupies a band of clear channel frequencies.
The foregoing description of the preferred embodiment of the invention has been
presented for the purposes of illustration and description. It is not intended
to be exhaustive or to limit the invention to the precise form disclosed. Many
modifications and variations are possible in light of the above discussions.
It is intended that the scope of the invention be limited not only by this detailed
description, but rather by the claims appended hereto.