SOUND MODULATION

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03153A002000120009-0
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 5
• Document Creation Date: December 27, 2016
• Document Release Date: June 20, 2014
• Sequence Number: 9
• Publication Date: October 12, 1954
• Content Type: MEMO

Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0
,
1
DOCUMENT NO.
NO CHANGE IN CLASS. 0
Li DECLASSIFIED
CLASS. CHANGED TO: TS S b it
NE-.X.T REVIEW DATE:
HR 70-2
DATF.-: fit in 4) I REVIEWER: 037169
crrrrT
Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0
STAT
Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0
SOUND MODULATING WRIMENT
1. The purpose of this equipment is: (1) To receive an audible sound
of any quality or pitch and by modulating it properly reproduce it in a
loud speaker as enunciated and understandable words. (2) electronieei4
fabricate sound of any quality, pitch or modulation required or desired.
2, the electronic modlition of sound to produce enunciated words may
be accomplished by the following circuits:
A. The electron emission potential of the cathode of a triode
vacuum tube is energised by a current that is created or
modulated by a continuous or any desired sound. A voice produced
signal ii connected to the control grid of the vacuum tube.
This the sound modulated electron flow from the cathode to
the plate is further modulated by the voice signal in the
control grid. The resulting signal passing through the plate,
when amplified in a loud speaker will have the quality of the
continuous sound modified to be heard as enunciated words in
accordance with the signal energizing the grid.
c Thow 0/90 ILO p's
Or SO id 4/0 eilcer SiofrAt- �
Mot:440TE 0
CUMAEkr
e 0,vrit, GRin EivE116.12 ro
c e. s (04A E
The Above circuit may be varied by introducing the continuous
sound modulated energy into either the control grid or plats
and the voice modulated energy into either the cathode or plate
to achieve the desired sound effects. A desired effect may also
be achieved by energizing the suppressor grid of vacuum tubes
with a voice modulated energy.
B. A constant sound may strike the diaphragm of a carbon or electro-
magnetic microphone that is energised by a voice modulated
current. The resat will be a signal with the quality of the
continuous sound modulated by the voice modulated current.
NA' e 'At PP Vs E
M0001-A.'rea ClitARSIA'r
1 I ',Lir Per
ceP's n+4ir-
Jim/re ro
Sri !IKE ro C--,
PM PH FUG.%
The modulation may be accomplished as shown above or the constant
sound may energize the microphone with the voice striking the
diaphragm whichever sound effect is desired.
C. A constant signal may be introduced into the coil of an electro-
magnetic speslicer. If the electromagnet of the speaker is energised
by a voice modulated energy the cone and coil of the speaker
will iberate with the quality of the constant signal but
modsaAted by the voice signal. AittSAU4freALALmAiri)wi-
re�tRIA1,44.frar PA S (4,4 (k YC ee t
trb'sg� tz a or YHCt
: Ssinahroce ea Itot sa-r
3.
'-Se54KEA ea Ire
Declassified in Part- Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0
Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0
3. Objectives (1) and (2) as stated in paragraph one above may both
be accomplished by the use of sound film strips and photoelectric cells.
The following methods and circuits can be utilized to produce enunciated
words from another sound&
A. A continuous or other desired sound can be made to activate a
light such as the AEO light. If this sound modulated light source
is permitted to directly activate a photoelectric cell the
resultant electric impulses may be amplified and the original
sound reproduced in a loudspeaker. If a voice carrying sound
film strip is introduced between the original modulated light
and the photoelectric cell 'whereby the light produced by the
continuous sound must pass through the voice wand strip the
resultant light striking the photoelectric cell will generate
a signal with the quality of the original sound modulated by
the voice sound strip.
114.mr 4ers'e4rs0
f3i, Sou of o
mkri Plfrepl
e4ritifri/vG-
30144,A9 .117
IA) T0 EL Arc rdie- d� 5 1 4
�
Lek-5 Ass AM 1141-
B. An exciting light can be focused through a sound film strip
that is carrying a constant sound. This modulated light will
again be focused through a sound film strip that carries a
voice. When this modulated and remodulated light strikes a
photoelectric cell a signal will be produced that has the
quality of the original sound but is modulated in accordance
with the voice carrying film strip.
AitAN e4iffi7lfr4 EIS RE
toterD
Orkt;r1:11� .4 AM,
� �
FILM e 41 at I" ro Alg
4-*
gemoscere.rlie Cadd.
sssmalic..
The relative merits of using sound film strips made by the
variable area method or the variable density method of putting
sound on film or a combination of the two would be determined
by practical application.
�AiaiLimari,4
Li* ft 4 13U f ON, *lir,
VA0'D A-4M S
r4/1148�0,4404 Er-secr IWO OSIA.47:i0A/
"f4q? F(44 41 Offi.e "e4fis-AP.1.1 P$Ai.s/r1-
Srlit.P it of r4m /41344
de rn
Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0
Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP8-03153A002000120009-0 1
� ^
�
4. It is to be noted that speech has dual charactelOstics. One is the
high frequency of the fundamental sound and the other is the low frequency
syllabic modulation of this sound by the movable parts of the human vocal
system.
5. In the production of the voice carrying sound film strip it may be
found desirable to elimintte the high fundamental frequency and leave only
the low syllabic frequency impressed upon the voice modulating film strip
as shown in the example below of a high frequency variable density sound
strip being modulated by a syllabic frequency variable area sound strip.
6. This syllabic frequency sound film strip may be produced in two
ways. (1) Exposing the raw film strip by a light that is activated by
a syllabic frequency. (2) Fabricating by hand a sound film strip with
the proper syllabic frequency serrations using the variable area method.
F
7. Sound film strips can be fabricated by hand and sound of any quality,
pitch or modulation required or desired may be produced. Pursuant to this
objective, conventinal sound film strips of the variable area type, of
various sounds and speech, can be. magnified, studied and analysed and the
general light configurations or seriations produced on the film by the
various sounds can be established. After such general designs have been
established a draftsman or artist can draw, on transparent film strip
material, proper serrations to produce any desired or required sound or
modulation thereof when this when this fabricated sound film strip is
passed between a light and lens system and a photoelectric cell that is
properly connected to an audio-amplifier and a loudspeaker. It must be
noted that the width of the fabricated sound film strip would be determined
by practical application, however, it can be judged by the magnification
required to enable study of conventinal sound strips.
8. Prior studies in the theory of sound have laid a good ground work
upon which the future of sound fabrication can be based. A great deal of
work has been devoted to perfecting methods of reproducing and mixing
sounds by mechanical and electrical means. However, the field of the
fabrication of sound has barely been touched.
9. Purity and pleasantness of musical sound has, heretofore, been
limited to musical instruments of fixed mechanical construction and to
a-lesser extent electric oscillators plus man's manipulation of these
instruments. The beauty and variety of sounds thus produced is not
questioned but it would be extremely shortsighted to assume that the
ultimate has already been achieved in the production of sound that is
pleasing to the ear or sounds that arouse other human emotions�
10. By using the method of painting the required serrations on trans-
parent film the possibilities for the fabrication of sound is limited only
by the imagination and creativeness of the technicians and artists.
3
Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0
Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0
11. A preleminary search has been made in the U.S. patent office to
determine the relation of this disclosure to prior patents. It was found
that Patent No. 2,151,091 issued March 21, 1939 to H.V. Dudley, Garden
City, New York, assignor to Bell Telephone Laboratories, provided for the
transmission of unintelligible voice signals that could be reproduced
into intelligible voice signals at the receiving end. The primary object
of the Dudley invention was to reduce the frequency range required for the
transmission of speech and the secrecy of such unintelligible signals from
interception.
12. Dudley based his invention on the fact that speech has dual character-
istics. One is the high frequency fundamental sound and the other is the
low syllabic frequency. He has divided the low syllabic frequencies into
ten parameters conforming to ten variable sections of the human vocal
system, that is tongue, lips etc., and has designed a system of ten circuits
that filter through these ten syllabic frequencies when a voice signal is
applied. The resultant signal has a frequency of low syllabi's pattern.
When this signal is received in a multi-oscillator circuit intelligible
words are reproduced.
13. Dudley Ala� invented an electronic device, patented June 21, 1938
No. 2,121,1142 which could be operated by hand and made to produce intell-
igible words. In this invention the ten fingers of the hand controlled
the syllabic frequency and a foot pedal controlled the volume. Other
inventions based on the Dudley concept emplained in patent No. 2,151,091
improved fidelity and modulated sounds of various types, however none
the systems employ the techniques set out in this disclosure nor do they
appear to have the fidelity or fabricating potential of this disclosure.
14. Prior patents which appear pertinent are:
2,121,142
Dudley
2,239,465
Dudley
20151,091
Dudley
2,458,227'
Vermeulen
2,183,248
Riesz
2,466,880
Dudley
2,243,089
Dudley
2,517,102
Flory
2,243,525
Dudley
2,635,156
Steinberg
20243,526
Dudley
2,640,880
Aigrain
2,243,527
Dudley
4
STAT
Declassified in Part - Sanitized Copy Approved for Release 2014/06/20: CIA-RDP78-03153A002000120009-0