LETTER TO (DELETED) FORWARDING STATUS REPORT TITLED (RESEARCH ON AN INTERROGATION DEVICE AND PROCEDURE) DATED MARCH 13, 1953

• Document Type: SPECIALCOLLECTION
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): 00184406
• Release Decision: RIPPUB
• Original Classification: U
• Document Page Count: 7
• Document Creation Date: January 21, 2025
• Document Release Date: January 15, 1983
• Publication Date: May 14, 1953

My 1), 1953
'.!ashInr;ton 2c, ^.
T1
C.-- rear
.TIclosed for 7!)ur flies is +, h61 originll copy
ef cr latent ":,tatus Etrport on the utie of the '7,iCe-tono deliv
instrument an an interroatien device. Us� (ncloned for your
use is a duplicate wirich you requested in your letter to us
dated February 20) 1953.
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Very tzul:i
Rosearch on an Interrogation revice and 7rocedure
�
May 13, 1953
The prin,Ary aim .11d purpose of this orojc:ct is to obtain a success..
ful interrogltion device from the effects of side-tone delay, together with
an appropriate procedure for its use iith a minimum number of attachments.
The secondary aim, being developed in this laboratory, is to obtain
morn easily Interpreted poly7,raph reords by use of Ade-tone delay in con-
junction Ilth the polyraph.
delivered to this labcratory a more
refined side-tone delay (TD) instrument on ffarch 5, 1953. The construction
of this new instrument was requested by the investigators Ath the belief
that its rnfinements would eliminate some of the difficulties encountered in
previous instruments. The refinements consii;ted of a variable tape mooed
muich vas incorvrated with the erase, record, and play,)ack nead aLisombly of
thc-! standard Magnccord. in order to accomplish this, A stand:1rd ?I'tgneccTd
recordinf: unit was completoly dismantled and tht7:n rebuilt ;:ith a variable
tape speed. Ilso the standard Magnecord synchronous moor wan adjusted so as
to drive a disc at variable distances fromthe axis. The newly constructed
drive was free from wow and had a 1-10 speed range which meant the tape speed
was 3" to 30" per second. This provided an easily adjustable variable in the
side-tone delay from 0.0)116 to 0.416 seconds, rho standard Hagnocorci endless-
loop tape device was utilized in pli,ice of the stand:Ard t.;,�o-reol device.
In February, 1953 the investigators decided that possibly better re-
sults could be obtained if the subject was not required to wear earphones.
Ili 71.3y 12.1 1953 additional a-paratus was added t,o v irtrible-delny
rent , so that it %wild be unnecessary for the subj.yct to L�ear earphone:T. Tho
elimination of the subject's earphones was accomplished by adding two throat
microphones, an auxiliary amplifier, and two extornal speakers.
The microphones are of VI, crystal-ccntact type and w..ire adan tod
throat mierortiones since no c.:-Thercial throat microba.)nes
The subject's microphone is connected to the 5 tandard Hacnecord amplifier,
and the amplifier's meter switch is the STD oFf-and-on switch. The Magnecord's
monitoring jack is the outlet from this instrument and it is connected to the
auxiliar� y amplifier by a sound cable. ale sublectil s.)eech poen throu4h this
,auxiliary 711741i-1er to the tvo enternal speakers. The second thrort microphone
interr;gat,:lr, .111 t iis icrc.onrne L conn(.:ctf.:.d I tvc tly to the
iliary am�lltfier, hricn hf-, two e xtern sic.
Thus, the sublect's 1!)er:ch in r delayed hlle the, interro-
r tor' s :::mcech can netTr be dflavod. :Ance tho to vies 1-rard thr,.�Th
the two external speakers, the subject will, be less likely to sulTect that his
voice is being delved because both voices will sound alike, even though the
interrogator's voice is not delayed.
*24.
Thrugh exreriment.ltion tt la7mr,Acry it .1:3 founi that
two external upeakers were much mord effective in inducing the TP effect
than one speaker. With only one speaker the subject can tarn his head and.
focus his attention wa.y� from the source of his delayed apeech. The bent
reeelts eeee LhtTLr1nc ticrL t.htve were olced on eithr side cf
the subject.
The variable-delay instrument delivered in March proved to be the
most durable so far tested because of its improved design and better con-
etructien. �nrovlded the :interrogator 1:ith an in7trumcnt which did not
htvl di nrhtn vow, flutter, or noises. .The v-;.!;igttors tilought thlt
this improved instrumfint would provide a better evaluation of the variable
delay because of there refinements. It wan believed that more subjects
vould,be affected by the side-tone 6e1ay phenomenon %d.ththAs improved in.
strument. Hoeevers in Pztual criminel crules it tan found that the subjPet3
-ho 'fere not affectedhy a prodeturnined 0.20 tpnconds delay Item usually not
2ff,:?ctrid Olen t r 1r3hLE..deLVy cfivicl! une?ds T117 wl!; true though
the. (n.tire I.:owe from 0.0)J16 to n.)11.6 F,acondrs W17 utUd.'urtharmores the
rubjecte orn vere affectod t.) nyoxtent by th predetorlind delay of 0,20
7coonds ,11:-7c!m IffnctA to 1,y groAtor xtent the -delay 1.41.e increased
or decreased. Then- results again indicated to the ineeetigators that possibly
the oubject's amount of educations intelligence or social consciQusness was
related to the ameunt of eifficulty he exoe-rienced in speaking when the 77D
instrument 44s operating.
Tt 11AS oriiellly thht that the mor diffi_culty a r,1111ty :!abject
had In flking because of the 7TP effet� the lore likely. hu 14-ks to oonfe7s.
However, it was discovored that many guilty subjects confessed oven though
their speech was unaffected by the STD device.
Thorefores lInce JanaA-y the InIrwItir-liors ';eru nc.), too (r,ncornod
the effect of the sift-tone delay ner se, bat thcy concentroted on the
procedures to be used with the instrument so thst confessions could be
more easily and readily obtained. The results, then obtained with the variable.
dalay Instrunont bore out this belief as well as the soundness of the olgn of
1-yArtm, nnre concerned clth int,IrrogJtional technittes rtlr! !Irecodures rathor
th4n 1,1th the !-crl effoct.
.It was Pound that approximately the same'percentage of guilty subjects
1
�
confessed I./hen the variable-delay instmtmInt was used fcr the interrogation
as when the one fixed delay instrument was used.
7rem t'x-k inocptin of thts
contract to ay 11, 1953 this bercentae of confessions fro7I interrocrAted
gatity �nuhlr,stm Rmounteri to Anproximltely 56 nqnt. M1.5 f:i.r.;ure of 56
pr,r cent can be cortm.lted to the ni7xcontar:c of crinnal k:-nfesdons v:linad at
llbor7.tory hot;41on Jannpr7 A, 12,41 pnd rec'r:mbor 31, 1952. Airing
this 13.,rv-7ear nz?riod, ,..henri. Ar!e-tone delf,y instrulonts 1.:ore used on these
inhjects, Approximltely 02 pk,r cent of the interrogated subjects did confess
to the crime under investigation.
Thua when one reviews the pant year in its entirely, it per that
the ide-tone delay did not incream the nercontage of confessions, 'hen A
confession was 7,ained by the use of the -11) instrument, It did not rilterially
0114
rcC.ucc virlte. !or 0;)tainin7, t11:1 n.ir (1Y
interroation any eaAer. urtMrnIre, tho
great majority of those who did confess would have confessed without the uee
of the f;TD instrument.
Tn 1 ct, Ltire ts� a yc:1 pabibj.3.ty t,hu ttv.z actually
:3turpcd a nurtcr cf :710*3eLl frcl conic;in titir crimarz. definitely
proven to be true in two cases when, after fully confessing, the subjects
stated that they ,t1A not confess��earlIer because of the 31D and that tey
14-21t, unttl the .71) in,s7tru!17:nt 1;a1 turn43d of: befure ILlso, it in
.).ther inLfn-rc.icionc tn iJJy uoj(ct3 were so.
confused F.nd beilticroll by the 7.1D offeCt that they were no longer ctncerned
about their crime and were not listening to w,hat the interrogator said. ',hen
tt; r3ubjact in ;Ictually d:Itractild 0.dr f.ile effects uf Lh th2 interregatorla
persaasivenens is lost ..r1A1 thefe is little likclihood of obtainir,F. a confession.
It isthe opinion of the inve3tigators that the. future hold:: very little
L2.2 f