|United States Patent
July 6, 1993
Method of recording and reproducing subliminal signals that are 180
degrees out of phase
A subliminal recording includes both subliminal message and mask signals
applied to both tracks of a two track recording medium. The subliminal
message signals are identical in content, and are recorded in an
out-of-phase relationship. The mask signals are recorded in phase. The
resulting recording may be utilized in the conventional manner for
subliminal recordings. By combining the composite signals in an inverted
relationship, the mask signals cancel while the subliminal message signals
are additive, thus allowing the presence of the subliminal message signal
to be confirmed on the recording.
Vavagiakis; Steven (118-17 97th Ave., Richmond Hill, NY 11419)
March 25, 1991|
|Current U.S. Class:
||434/319; 381/73.1; 434/236; 600/28 |
||G09B 005/04; G09B 019/00; A61M 021/00; H04R 003/02|
|Field of Search:
U.S. Patent Documents
|4395600||Jul., 1983||Lundy et al.||381/73.
|4658306||Apr., 1987||Daigaku et al.||360/22.
|4777529||Oct., 1988||Schultz et al.||434/307.
Primary Examiner: Apley; Richard J.
Assistant Examiner: Leubecker; John P.
1. A method for the recording and subsequent reproduction of a subliminal
message recording, comprising the steps of placing both a subliminal
message signal and a mask signal upon first and second tracks of a
recording medium for simultaneous playback, said subliminal message signal
on each of said tracks being of identical content and in a 180.degree.
out-of-phase relationship, said mask signal on each of said first and
second tracks being of identical content and in an in-phase relationship,
the amplitudes of said subliminal message and mask signals being chosen
such that the subliminal message signal cannot be perceived upon playback,
and playing back each of said tracks through a separate channel of a
multi-channel playback apparatus.
BACKGROUND OF THE INVENTION
The techniques of training or teaching through the use of subliminal audio
signals is well known, as presented, for example, in U.S. Pat. No.
3,060,795 to Corrigan and U.S. Pat. No. 3,278,676 to Becker. In such
methodology an audio recording, typically on audiotape, is prepared with a
recording of a desired spoken message at a first, low volume. This is the
subliminal message signal. A second audio signal, typically music, is also
impressed on the recording medium at a second, higher amplitude. The
second signal masks the first such that the first cannot be perceived by
the listener upon playback. The theory of subliminal perception states
that while the first, subliminal signal cannot be perceived in the normal
manner, its existence on the recording medium and playback at a subliminal
level results in the unconscious receipt of the signal and a corresponding
effect upon the listener. Depending on the content of the subliminally
recorded message, such recordings have been used for a variety of training
regimens, such as weight control, smoking cessation, memory development,
and the like.
Because a subliminal recording, by definition, includes a message signal
which is not intended to be consciously perceived by the listener in the
normal manner, the listener is not likely to be consciously "aware" of the
existence of a subliminal message in a recording. Despite some questions
as to the actual effect of such signals, prohibitions exist against the
use of such material in certain situations, such as in broadcast
advertisements, to guard against the presentation of such material to
those not consenting to its use.
On the other hand, the user of a subliminal recording has the vital concern
that the intended subliminal message is in fact there. The user, having
invested in the recording, properly has the interest that, for example,
the stop-smoking tape he purchased does indeed have a motivation message
to assist him or her in his quest. In addition, the user may wish to be
assured that the content of the subliminal track is acceptable, and does
not contain material which he or she would find objectionable or improper
for the intended purpose. Since the very essence of a subliminal recording
is that the subliminal message cannot be perceived normally, that quality
serves as a bar to verification of its existence.
Other than at the master recording level, where the subliminal and
supraliminal mask signals are blended together and thus can be identified,
it's extremely difficult to confirm the existence of a subliminal message
signal on a recording. This leaves the recording manufacturer with the
risk of claims that the subliminal message is non-existent or other than
what it is alleged to be, and places the user of the recording in the
uncomfortable position of being unable to verify the legitimacy and
suitability of the product he has obtained.
It is accordingly a purpose of the present invention to provide a
subliminal recording bearing a subliminal message track, the presence of
which can be verified using a minimal amount of equipment.
Another purpose of the present invention is to provide a subliminal message
recording which can be verified by the user.
Yet another purpose of the present invention is to provide a subliminal
message recording in which the level of the subliminal recording can be
raised without damaging the subliminal nature of the track.
SUMMARY OF THE INVENTION
In accordance with the above and other and additional purposes and objects,
the present invention comprises an audio recording and a method of making
same in which the recording has a subliminal message signal and a masking
signal mixed together. A stereophonic or two track recording process is
utilized, in which a monaural masking signal is placed on both tracks in
an in-phase relationship. A monaural subliminal message is also placed on
both tracks, but in a 180.degree. inverted phase relationship between the
tracks. The masking signal and the subliminal message signal for each
track are combined in the normal manner for a subliminal recording, the
relative amplitudes of the signals being chosen such that the subliminal
signal is masked by the other signal. The resulting recording can be used
in the conventional manner on stereophonic or monaural playback equipment.
To verify the existence of the subliminal message signal, the signals on
the two tracks are combined in a 180.degree. relative phase relationship.
Because the masking signals on the two tracks were recorded in phase, the
inversion places them in a cancelling relationship, such that the masking
signal cannot be heard. The subliminal message signals, on the other hand,
being recorded in an out-of-phase relation, are placed in phase by the
conversion, such that the signals are combined and become audible. Thus
the listener hears only the subliminal message signal and can confirm the
existence of the normally-inaudible message. A further benefit of the
present invention is that the subliminal message can be recorded at a
higher amplitude, the out-of-phase relationship between the left and right
channel signals on two track playback providing a further deadening effect
to conscious perception of the message.
BRIEF DESCRIPTION OF THE DRAWINGS
A fuller understanding of the present invention can be accomplished upon
consideration of the following detailed description of a preferred, but
nonetheless illustrative embodiment of the present invention when reviewed
in connection with the annexed drawings, wherein:
FIG. 1 is a representation of in-phase and out-of-phase signals; and
FIG. 2 is a representation of a cable able to provide a 180.degree. phase
shift between signals as required in the present invention.
FIG. 3 is a representation of the steps required to record and reproduce
the subliminal signal.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
As depicted in FIG. 1, a generalized waveform 10 such as signal A.sub.1 has
both positive and negative going portions 12, 14, respectively, with
respect to a baseline. While the figure depicts a sinusoid of a single
frequency, fourier analysis teaches that complex waveforms, such as that
generated by music or speech, can be defined as a combination of a series
of sinusoids of varying amplitudes and frequencies. When two sinusiods of
the same frequency have their respective peaks and zero-crossings aligned
in time, the signals are in phase, and the combining of the signals
results in a signal having an maximum amplitude equal to the sum of the
amplitudes of the individual components.
When the peaks and zero crossings of two signals of the same frequency are
displaced in time by the equivalent of one-half the period (180.degree. or
.pi. radians), the signals are said to be fully out-of-phase, and the
combination of the two signals results in a cancellation of the signal.
Thus, if an audio signal is combined with an otherwise identical signal
180.degree. out of phase with it, cancellation of the two signals results.
Because of certain nonlinearities of a complex signal, the cancellation
may not be complete, but the degree of cancellation is significant and
causes a meaningful diminution, if not complete cancellation, of the
Signals A.sub.1 and B.sub.1 represent the masking signals applied to
channels or tracks A and B of a convention stereophonic recording,
typically on audiotape. These signals are identical, are in phase with
each other, and typically consist of music chosen in accordance with the
nature of the subliminal message to be recorded or as otherwise desired.
Signals A.sub.2 and B.sub.2 represent the subliminal message similarly
placed on the tracks A and B of the recording medium. These signals are
again identical in content, but as shown are 180.degree. out of phase with
each other. The amplitude of the recorded subliminal message signals on
each track is less than that of the amplitude of the masking signals as
The subliminal recording of the present invention can be produced using
conventional recording apparatus. In general, any equipment capable of
producing a two-track (stereo) recording can be used. The subliminal
message signals may be produced using a cable 16 as shown in FIG. 2, in
conjunction with a conventional microphone 18. The cable 16 consists of
two signal leads 20, 22 within a typically coaxial ground lead 24,
providing a balanced signal on the leads with respect to the ground. As
known in the art, one of the two signal leads is identified as the "hot"
or "positive" lead, although for the present invention, either lead may be
so designated. Such a designation allows polarity-correct connections to
The cable is formed into a Y configuration, yielding a first input end
terminal 26 and a pair of output terminal ends 28, 30, each of which
serves as the input to one of the channels of the recording apparatus 32.
The sense of one pair of terminal leads is inverted with respect to the
other such that, for example, if lead 20 was designated as the hot lead at
terminal 28 lead 22 is considered the hot lead at terminal 30 for purposes
of connection to the recording equipment 32. This inversion results in the
signals at the terminals 28, 30 being 180.degree. out of phase to each
The recording of the subliminal track is made such that there is no
crossover through the recording apparatus 32 from one channel to the
other. This typically can be insured by panning the respective channels
full left and right to avoid mixing of the channel signals. Each of the
recorded tracks thus contain exclusively one of the out-of-phase signals.
The subliminal signals can then be combined with the in-phase masking
signals. The masking signal applied to both channels should be fully
monaural, insuring that it is identical on both channels. The use of delay
lines, harmonizers and the like is to be avoided as they can alter the
phase relationship between the channels. The subliminal and masking tracks
are combined on the recording media by appropriate means as known in the
art, such as through a mixer, or by overrecording.
The resulting recording, bearing in-phase masking signals and 180.degree.
out-of-phase subliminal message signals, may be utilized in the
conventional manner where each track is played over a separate channel for
subliminal messaging, either one or both channels being played. Because
the subliminal message signals are 180.degree. out of phase, they can be
recorded at up to about a 3 decibel increase over conventional subliminal
tracks for two track or stereophonic playback, as the spatial cancellation
of the out-of-phase signals upon playback provides a greater degree of
masking than in conventional subliminal recordings.
To confirm the existence of the subliminal message signal, the cable of
FIG. 2 can again be used, wherein the terminals 28, 30 are each connected
to a channel output of stereophonic playback equipment and the terminal 26
is connected to a speaker or the like. With the recording played back in a
balanced mode, the cable inverts the input signals such that the masking
signals, which were recorded in phase, are inverted and combined to cancel
each other out at terminal 26. Accordingly, the mask track is no longer
audible. The subliminal message signals, on the other hand, being
inverted, are reinverted an additional 180.degree., resulting in a
360.degree. shift, allowing the signals to be additive, whereby the
combined signal becomes audible. Confirmation of the existence of the
signal is thus established.
* * * * *