TEXT OF LETTER RE OSCILLOSCOPIC DEVICES WITH ATTACHED ROUTING SHEET

Document Type:

SPECIALCOLLECTION [1]

Collection:

General CIA Records [2]

Document Number (FOIA) /ESDN (CREST):

00184359

Release Decision:

RIPPUB

Original Classification:

Document Page Count:

Document Creation Date:

January 21, 2025

Document Release Date:

January 15, 1983

Sequence Number:

Case Number:

Publication Date:

May 10, 1951

File:

Attachment	Size
TEXT OF LETTER RE OSCILLO[12884950].pdf [3]	123.84 KB

Body:

UNCLASSIFIED RESTRICrED CONFIDENTIAL - NDER WILL CIRCLE l'ASSIFICATION TOP CENTRAL INTELLIGENCE AGENCY OFFICIAL ROUTING SLIP AND �..,,TOM) 4"177 INIT ALS SECRET CV DATE TO ' ' 1 Assistant Deputy (Inspection sprwrity) 2 _Arid 3 4 5 \ , FROM 1 INITIALS DATE 1 Deputy_Adviaor_forum4pmenti__ -7ft7,11/ 2 3 from APPROVAL INFORMATION SIGNATURE ACTION DIRECT REPLY ,RETURN COMMENT PREPARATION OFREPLY DISPATCH CONCURRENCE RECOMMENDATION FILE , .RKS: This is a text of a letter received Would you please uc th s bac. with an ndication as to whether or not there appears to be an Agency application: either domestically or overseas. SECRET CONFIDENTIAL RESTRICTED /UNCLASSIFIED FORM NO. 30.4 SP 1947 We have some electronic equipment which we believe may be of interest to you. It is made up of four separate units. The first unit is a tape recorder of extremely high fidelity capable of reproducing in intimate detail all the inflections, nuances, and tones encountered in human speech. The recording can then be played back through the second unit, a specially designed oscilloscopic device which flashes on a screen in the most exact detail a moving picture of these inflections and tonal qualities. The third unit may be employed to halve the speed of the recording and, in turn, to double the resultant sound frequency thus providing a geometrically perfect picture of a spoken word with this picture moving at a rate slow enough to permit careful visual examination. A fourth unit permits the transfer of these oscilloscopic curves to a permanent paper record for static visual analysis and comparison. This equipment group can be used in making almost micrometric analyses of the speech characteristics peculiar to a particular locale. Direct com- parisons can be made of the speech habits of individuals known to come from a particular place with those of another person allegedly from the same place but who may be suspect. This same equipment may be used for polishing away speech habits which might result in the detection of an operative. We would appreciate an opportunity to discuss this matter with you in greater detail at your convenience.