EMPLOYMENT OF ULTRASONIC WAVES AS A METHOD OF UNCONVENTIONAL ATTACK

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP84-00022R000300160037-5
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 2
• Document Creation Date: December 16, 2016
• Document Release Date: September 7, 2000
• Sequence Number: 37
• Publication Date: April 20, 1951
• Content Type: MEMO

approved For Releas '005/01/10 : CI 1& 4-00022RO0030:QV0037-5
CENTRAL INTELLIGENCE AGENCY
OFFICE OF SCIENTIFIC INTELLIGENCE
20 April 1951
SCIENTIFIC INTELLIGENCE MEMORANDUM, 51-4
SUBJECT. Employment of Ultrasonic Waves as a Method of
Unconventional Attack
1o The ICIS Subcommittee on Defense Against Unconventional
Attack has requested an evaluation of the possible employment of
ultrasonic waves by the USSR as a method of unconventional attack.
2. By means of electronic devices, it is possible to
produce ultrasonic waves which would be inaudible but unbearable
to humans, and reasonably successful experiments have been
conducted on animals in both the USSR and the United States.
However, the present equipment is unduly bulky and mast be operated
too close to the intended victim to be a practical method of
unconventional attack. It is most unlikely that the fundamental
physical limitations on producing high sound fields in air by
means of electronic devices can be overcome within the next five
years to pelt development of equipment suitable for unconventional
attack.
3. Therefore, employment of ultrasonic waves by, the
USSR in an attack upon the United States between now and 1956 is
considered highly improbable.
Arprcffedor Release 2005/01/10: CIA-RDP84-00022R000300160037-5
25X1
 A,proved For Releas 05/01/10 :
LBKW
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05/01/1
: CIA-RDP
4-00022R000300160037-5
FORM NO. 51 10 SECRET
APR 1949 n'S