Voice Stress History

3.0 Background / Historical Aspects

Mankind has sought methods of separ= ating truth from deception throughout history.&n= bsp; In the most recent hundred years, that objective has primarily addre= ssed physical aspects which might reflect detectable change when the subject is under the stress of some jeopardy (threat to freedom) situations. This sect= ion outlines significant events in that historical record.

3.1 Origins

= In the history of lie detection, there are many stories of inventive procedures to determine if a person were lying. For example, centuries ago one method was said to employ the tail of= a donkey. According to the lege= nd, the donkey was placed in a darkened tent, and its tail was coated generously with lampblack. The list of criminal suspects were instructed to go into the tent, one at a time, and p= ull the donkey’s tail. They were told that the donkey would bray if a liar pulled its tail. The honorable men went into the tent, one at a time, and pulled the donkey’s tail, and each came out with hands soiled by the lampblack. The deceptive man came out with clean hands; since he was afraid= to pull the tail for fear that the donkey would bray. He was therefore known as a liar s= ince he had lied about pulling the tail.

Another of = the first psychological standards employed in determining truth and deception c= omes to us from ancient C= hina. A group of subjects being interrog= ated were given a mouthful of dry rice. Each was interrogated and then given a command to spit out the rice into his hands. The subject with the dry rice = was deemed the liar and promptly beheaded. The theory had to do with the autono= mic fight or flight response, one characteristic of which is the drying of the mouth under stressful conditions.

Since the time of these early reco= rds to the present, many methods and techniques have been developed for recogni= zing truth, deception, right, wrong, justice, and so on. They have ranged from psychological approaches to purely instrumental techniques, and combinations of the two.<= span style=3D'mso-spacerun:yes'> History shows the ordeal was the standard, socially acceptable method for dealing with deception. The ordeal ran the gamut of an imaginative array of techniques to expose truth. Some were simple physical abuse, h= ot irons, mortal combat, dunking, and burning at the stake, to name but a few.=

Prior to the turn of the century, Cesar Lambroso, of I= taly, experimented with measurement of pulse and blood pressure changes to determ= ine truth or deception in the answers given by actual criminal suspects. Lambroso’s research was not fully documented, and his pioneering work= in the application of instrumentation to truth determination was not pursued.<= span style=3D'mso-spacerun:yes'> Other experimenters, including Wil= liam Moulton, Vittorio Benussi, and John L. Larson, pursued the subject, and add= ed significantly to the growing body of knowledge in the field.

Modern techniques for truth determination are probably most closely related to Leonard Keeler’s 1= 920s work. He modified existing apparatus to be applied to the discovery of emotional complexes. Keeler’s modified existing apparatus foretold the modern polygraph instrument through its use of measu= red changes in blood pressure, skin resistance, and pneumographic characteristi= cs, due to the incursion of applied stress to the human body. Keeler introduced the Kymograph, a motor-driven recorder that accurately delivered chart paper to one or more = pens that produced graphic analogs to the various stress indicators to be studied. A fairly crude quest= ioning technique was developed to initiate biological changes that were recorded by the Kymograph and subsequently interpreted by the examiner, in terms of str= ess reactions to jeopardy situations introduced by the questions. The technique is still used today,= and clear similarities exist with Keeler’s original approach.

In 1964, Colonel Charles R. McQuis= ton coined the term voice stress analysis as part of an Army requirements docum= ent written to define the need for an instrument to supplant the polygraph, wit= hout the need for direct connection to the subject’s body and which would cause no lasting physical or psychological harm to the subject. McQuiston, Wilson Ford, and Alan B= ell, US Army Intelligence officers, later retired, and developed the first instrume= nt to satisfy that Army requirement. The prototype of the Psychological Stress Evaluator (PSE) was comple= ted in January, 1971. The PSE rel= ied on measuring stress-induced changes to the muscle micro-tremor, as displayed involuntary changes in the voice. The PSE employed a single-pen heated-wire Electrocardiogram (ECG) or EKG chart recorder to describe the changes to the micro-tremor, which is a signal from the central nervous system to manage t= he body’s response to stress. In 1970, Bell, McQuiston, and Ford founded Dektor Counterintelligence and Security, Inc., which would produce the PSE. = The PSE, applying voice stress analysis, represented the first major advance in= the field, since the kymograph was introduced in the 1920s. The PSE is illustra= ted below.

The PSE was dominant in stress analysis for some 12 years, until the Verimetrics System, also invented by Charles McQuiston, permitted the analytical proces= s to take advantage of the emerging personal computer to more conveniently and efficiently produce the charts. Various evolutionary models of the Verimetr= ics System are shown on pages 18 ,19 and 21.

PSYCHOLOGICAL STRESS EVALUATOR&nbs= p; (PSE)

&n= bsp; The Computer Voice Stress Analyzer (CVSA) System, marketed by Charles Humble, claimed the capability for real time analysis to the baseline PSE. Real time apparently means that the interview may be committed directly to the instrument, without the intermed= iate step of magnetic tape recording.

The Verimetrics V-5000 Computer-based system has been the most advanced

VERIMETRICS LL 1000

Voice stress analysis instr= ument on the market. Since its introduction, the V-5000 has been regularly updated, both in terms of its hardware and software, and is expected to remain a dominant force in the fi= eld for some time to come.

Now, The Diogenes Company, has tak= en the basic theory of the Verimetrics instrument a step further with introduc= tion of The Diogenes Voice Stress Analysis System. The Diogenes System represents the current state of the art in digitized voice stress analysis, having achieved a complete voice analysis capability, real time recording (if desired), modernized software, and unparalleled portability.

3.2 The Frye Case.

In our co= urtrooms today, there is an unacceptable level of intentional perjury. It is usually difficult, and often impossible for even an experienced trial lawyer to expose the lies of a false-swearing witness. Some = means is needed to reliably identify deception in sworn testimony! In 1923, a scientific test of credibility was offered by the defendant in a homicide case in an attempt t= o establish his innocence, but the court did not allow it. The defendant, one James Alphonzo = Frye, offered the testimony of a Dr. Marston, that he had been subjected to a deception test, which had demonstrated the truthfulness of his denials of guilt. The instrument was a forerunner of the polygraph. = The trial judge rejected this evidence, and the ruling was appealed to the U.S. Court of Appeals that affirmed

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“Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. And while courts go a long way in admitting expert testimony deduced from a well-recognized principle of discovery, the thing from which the deduction is made must be sufficiently established to have gained general scientific acceptance in the field in wh= ich it belongs.”

“We thi= nk the systolic blood pressure deception test has not gained such standing and scientific recognition among physiological and psychological authorities as would justify the courts in admitting expert testimony deduced from the discovery, development, and experiments thus far made.”

Frye vs. the United States, 293 F. 1013, 1= 014.

Despite = the sound legal reasoning upon which the Frye decision was based, in fact justi= ce was poorly served. After spen= ding three years’ of a life sentence, Frye was exonerated by the confessio= n of the actual killer, and was released. The clear conclusion seems to be that lawyers, judges, law professor= s, and lawmakers can no longer assume a complacent attitude towards current methods to expose Mendacity (perjury).

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3.3 The Polygraph

&n= bsp; The most familiar image of the polygraph instrument is that of a paper chart recorder, with several ink or thermal printing pens gyrating over the paper= , or polygram, as it is fed out of the machine.

VERIMETRICS 3000 CIRCUIT CARD
      The standard polygram is six inches wide and includes three or more items of graphic data, shown as traces: the cardiogram (blood pressure), the pneumogram (changes in rate of breathing),= and the galvanic trace (changes in electrical resistance in the skin. As many as 32 traces have been demonstrated. Each trace reco= rds changes to a bodily characteristic, which is affected by stress and can be analyzed to assess the meaning of the reaction. The cardiogram trace reflects chan= ges in blood pressure and pulse rate. The pneumo trace shows change in the respiratory rate. The galvo trace monitors changes i= n the electrical resistance of the skin. &n= bsp; A representative sample of the pen traces is provided on page 24<= span style=3D'mso-bidi-font-size:11.0pt;line-height:150%'>. From the bottom, the fi= rst trace is blood pressure, also carrying pulse rate; the second is the galvan= ic skin response; and the third and fourth are respiration rate measurements.<= /p>
      The cardio pen is primarily driven= by blood pressure, and reacts to increased blood pressure with an upward movemen= t, and to decreased pressure with the opposite motion. It will reflect an increase in pum= ping action by showing an increased frequency, and will indicate a stressful response from the subject by reflecting changing patterns of heart valve activity. The latter will sho= w up in the dichrotic notch, moving up or down within the heart cycle. This indication is responsive to t= he opening and closing of the semilunar valve. The subject’s pulse rate is = shown superimposed on the blood pressure waveform, as a series of spikes, which c= an be easily distinguished.

The pneumo pen responds to the breathing cycle of the subject, as he inhales and exhales, by recognizing the expansion and contraction of his chest. A pair of air-filled rubber tubes = around the subject’s chest reflects these expansions and contractions throug= h a corresponding rise and fall of the air pressure within the tube. This pressure is converted to a mechanical motion at the pen, as it is driven high and low to produce an ink trace as an electronic analogy to the subject’s respiration.

    The galvo pen tracks Galvanic Skin Resist= ance (GSR). It measures electrical resistance to a small direct current passed through the subject’s ski= n, between two electrodes attached to the fingers or the palm of the hand. If the subject responds to a quest= ion with a stress reaction, the current passing through the lowered resistance = will increase and the pen will rise on the chart. The magnitude of the pen reaction = is directly proportional to the strength of the reaction.

      The three (or more) pens can provi= de about nineteen major indicators for use by the examiner in evaluating the stresses present in the subject. These indicators are produced by measurable variations in organic fu= nctions after a predictable reaction period. The delay, coupled with the mechanical limitations of the instrument= and its sensors, makes interpretation difficult. Despite these difficulties, polygr= aph charts can be interpreted with up to 95% accuracy based on the skill= of the examiner.

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3.4 The General Questions Test=

      The Polygraph, the forerunner of stress-analyzers, required some techniques of questioning that established the means for defining the differences betw= een questions which were intended to produce a normal response, and those which were relevant to the issue at hand. In the beginning, the answers to relevant questions, such as “= Did you steal the money?” were simply compared to the irrelevant question= s, such as “Do you live in = Tucson?” It soon became clear that a consis= tent procedure had to be developed in order to maximize the utility of the polygraph. From 1927 until into the 1950s, the General Questions Test (GQT), also sometimes called the Relevant / Irrelevant Question Test, filled that requirement. It is now considered useful only to confirm a confession.

The = GQT was normally structured as follows

a.      Is your name Mary Smith?

b.      Do you live in Virginia?

c.      Do you know who stole the money?<= /i>

d.      Do you drive a car?

e.      Did you steal the money?

f.      = Are you mar= ried?

g.      Do you know where the stolen money is hidden?

h.      Do you live in Tucson?

i.      = Have you ever stolen anything since the age of 12?

j.      = Do you = like to eat candy?

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Questions c, e, and g are clearly the relevant questions, = and are self-explanatory. Questio= ns b, d, f, h, and j are the control questions that are to serve as the basis for comparison. Question i. is called the Known Lie Control Question. During a pr= etest procedure, the examiner would ask the subject to deliberately lie to this question, to create a record of patterns responding to a test lie. The examiner would ask the subject= in a leading, negative style, such as “I’m sure you would not have stolen anything after 12 years of age because you are not that kind of person!” The examiner w= ould shake his head while asking the question, in order to indicate to the subje= ct what the desired answer was. = The theory of the Known Lie Control Question was that once the subject was tric= ked into lying during the pretest, he had no choice but to continue lying in the main test. The subject probab= ly mentally reviewed incidents in his past that he did not want revealed,

And would cause a polygraph reaction, which could be compared with the relevant questions of the main t= est.

      The GQT and its Known Lie Control Question was a risky procedure. It raised the possibility of eroding the subject’s confidence in the examiner, once he understood that he had been tricked into providing a samp= le lie signature. The response m= ay not be truly comparable to those of the relevant questions in the main test, an= d; it requires extraordinarily sophisticated examiner skills to use the Known = Lie Techniques. Cleve Backster, a leading polygraph examiner of the time, recognized the shortcomings of the = GQT, particularly in its inability to factor in the influence of outside issues.=

Polygraph Traces

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An example, what if the s= ubject shows stress actually resulting from another transgression than the one, he= is being tested for? How can the distinction be made? About one person in ten is generally expected to be a true guilt complex responder, w= ho will show heavy stress in reaction to any accusatory question, whether he is guilty or not! Backster devel= oped Zone Comparison Testing as a means of revealing those stresses produced by outside influence and by guilt complex reactions. His Zone of Comparison (ZOC) test employed carefully selected control questions to eliminate those confounding conditions from the analysis. The ZOC, is still in use today by both polygraphers and voice stress examiners, will be discussed in Section 6.

3.5 The Kubis Study

      In the mid-I970s, Dr. Joseph Kubis= , a researcher from Fordham University, conduct= ed a study on behalf of the US Army, to evaluate the utility of the Psychological Stress Evaluator (PSE). Dr. K= ubis concluded that voice lie detection instruments may not be accepted as valid= lie detectors within the constraints of an experimental paradigm. In other words, the system did not= work in the laboratory environment. The Washington Post reporting on the release of the study by a member of Congre= ss, said that it proved that VSA was inferior to the polygraph. Dr. Kubis made no judgment on the utility of the system in actual criminal investigations, although he believ= ed it should be tested in the field. Dr. Kubis’ study was actually carri= ed out by an assistant, Dr. William J. Krossner, coincidentally a polygraph examiner.

      The Kubis study involved the use of college students participating in scenarios of extremely artificial crime situations. The technique was called the triad test approach. Kubis also obtained poor results, slightly better than chance, with = the accepted polygraph system using the triad test approach. Neither Kubis or Krossner ever ope= rated a PSE as part of the test, but rather shipped the tapes by mail to another individual who interpreted them. That individual was Dr. Gordon Barland, of= the University of Utah. Barland said that the Kubis record= ings were of extremely poor quality, having been made at a low recording level, = and with the microphone too far from the subject. Some of the tapes had to be reject= ed and returned as unsuitable for testing. Dr. Barland also said that far better results would have been achiev= ed had actual high-stress situations been employed, rather than those of the l= ow-stress triad test environment.

      The US Army= did not endorse the Kubis study, and is on record indicating that release of the study does not suggest Army acceptance or endorsement of findings and conclusions of the study. The Diogenes Company believes that the Kubis study, due to the low-stress test technique, and the poor quality of its interview recordings, is invalid as a measure of VSA effectiveness. The statements of study participants tend to support the position that the test= was ill conceived and poorly structured.

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3.6 The Psychological Stress Evaluator (PSE)<= /p>
      Three retired Army Officers, Allan Bell, Jr., Charles R. McQuiston, and Wilson Ford developed the PSE. These men responded to an Army int= erest in a remote lie detector, with a concept based on recognition that emotional stress induces measurable change into the human voice. This change could be found in a tr= emor associated with contraction of muscles, effecting minute oscillations at a frequency of about eight to fourteen Hertz (cycles per second).

      The amplitude of these oscillation= s is a fiftieth or less of that of the total contraction. While all muscles exhibit this tre= mor, the PSE concentrates on those associated with the human voice. In the voice the tremors occur at essentially the same time the stress is experienced, permitting analysis of long, narrative answers, rather than the carefully-timed yes or no required= by the polygraph, with its inherent delayed reactions.

      The PSE capitalized on Colonel McQuiston’s discovery that the psychological tremor disappeared under conditions of stress -- fear, anxiety, excitement, and the like. The PSE instrument is able to dete= ct and record the presence or absence of the tremor to indicate whether the subjec= t is under emotional stress or not. The PSE represented the breakthrough technology in voice stress analysis, and introduced remote stress detection, freeing the subject from the restrictive straps, wires, and bladders of the polygraph system.

      In 1970, Bell, Mcquiston, and Ford founded Dektor Counterintelligence and Security, Inc., as a vehicle for providing various types of physical security services. Eventually= , via Dektor, the three developed the PSE and began to manufacture and market the system. Several thousand units were sold in the = United States and overseas.

3.7 The Carnahan and the Heisse Studies

The Carnahan House Conference on Cri= me Countermeasures was held at the University of Kentucky in 1976= . Proceedings of the conference conf= irmed that the PSE was indeed a superior voice stress analyzer in high-jeopardy t= ruth and deception determinations. It was pointed out in the study, any such system can be effective only when operated in conjunction with a proper psycho-physiological test structure.<= span style=3D'mso-spacerun:yes'> The conference proceedings include= d a study entitled Audio Stress Analysis: A Validation and Reliability Study of the Psychological Stress Evalu= ator (PSE), wherein Dr. John W. Heisse, Jr. reported a validity and reliability, utilizing the PSE with a structured testing format, of 96.12%. This was the first such study usin= g live cases, and no synthetic issues. A subsequent (1992) publication by Dr.’ John W. Heisse, Jr., The Verimetrics Computer System, a Reliability Study, compares the reliability of the Verimetrics computer-based system to the known reliabili= ty of the Psychological Stress Evaluator (PSE). Heisse used the theory that indivi= duals react to colors, and that they have conscious and unconscious biases, prejudices, and emotions related to color.= He postulated that a given group of subjects would show more stress = to one color than another. The variation was to be measured by both the PSE and the Verimetrics system. The tests included no actual jeopa= rdy for the subjects, and the subjects did not know what the examiner was looki= ng for. Heisse concluded that the color hypothesis is valid, and that individuals show vocal change to emotio= ns produced by color, either at a conscious or unconscious level. He concluded that, while the PSE a= nd Verimetrics systems measure the vocal changes, the latter has a far higher reliability, and employs a much simpler criteria for reading chart patterns. The Verimetrics sys= tem consistently provided better, more readable chart patterns than did the PSE= .

3.8= = The Verimetrics Voice Stress Analyz= er

Charles McQuiston want= ed to advance the state of the voice stress analysis art, to permit demonstrat= ion, by comparative analysis, the human physiological condition at any microseco= nd of time. He identified the fo= llowing challenge in his quest for an improved voice stress analyzer: To program a computer to identify = an infinite number of frequencies involved with human speech and then display a graphic representation of said frequencies for analysis. This was the problem he attacked a= s he developed the Verimetrics system as the logical successor to the PSE, which= had served, virtually unmodified, for some twelve years. He speculated that the required equipment would be a computer with an on-line printer and a good cassette t= ape recorder.

      His objective system would include collection of the subject human speech via the tape recorder; entry of the audio signal into the computer, where every frequency involved could be identified and displayed via the graphics printer. Each frequency, with its entire harmonics, would be identified on the computer printout in order to determi= ne the relationship of each frequency to each of the other frequencies in succeeding audio displays. In= this way, McQuiston reasoned, it would be possible to determine the effects of physiological changes imposed on the human voice by the autonomic nervous system and the central nervous system.