Boyd Polygraph Service
Frequently Asked Questions
P.O. Box 29426
St. Louis, MO 63126
Phone: (314) 706- 7087
Copyright ©2012 Boyd Polygraph Services
Designed by DKD Designs
Last Modified 1.11.2012
Polygraph vs. Voice Stress
While polygraph examinations have been developed over the course of one hundred years and have shown consistent accuracy in scientific research, recent innovations have attempted to use voice stress analysis for the same purpose. However, studies have been unable to prove accuracy or reliability with regard to voice stress technology.
In the position statement of the American Polygraph Association, President Richard W. Keifer states, "Current scientific evidence establishes the polygraph as the most accurate means of detecting deception. Recently there have been claims made that voice stress analysis is an accurate means of detecting deception. There is no independent research supporting the assertion that voice stress analysis is an accurate means of detecting deception. The APA does not endorse the use of voice stress analysis to determine or detect deception."
The Department of Defense Polygraph Institute makes the following conclusions in their voice stress analysis position statement:
To date, we have found no credible evidence in information furnished by the manufacturers [of voice stress analysis equipment], the scientific literature, or in our own research, that voice stress analysis is an effective investigative tool for determining deception.
A very few studies have found that voice stress analysis worked better than chance at detecting deception. Unfortunately, these results are not consistent, nor are the reported accuracies nearly as good as those normally reported for the polygraph.
The preponderance of evidence indicates the polygraph is far more accurate at detecting deception than is voice stress analysis. No Department of Defense agency uses any form of voice stress analysis for investigative purposes."
The position statement of the American Association of Police Polygraphists states, " The AAPP has found no scientific studies or independent research which support voice stress analysis as a method of discriminating between truth and deception. Until voice stress analysis is supported by scientific research that conclusively demonstrates its validity and reliability, and American Association of Police Polygraphists will not endorse the use of such equipment in the law enforcement community." It also identifies polygraph as "the only deception detection device which has the scientific support and has earned judicial acceptance for expert testimony [in court proceedings]."
Source: American Polygraph Association
Accuracy and Validity
Polygraph vs. Voice Stress
How is the polygraph conducted?
The examination begins by advising the examinee the complete session will be
monitored and recorded which is a requirement of the American Polygraph Association.
Next the examiner explains how the test will be conducted.
Personal information is obtained (required by APA standards)
An in depth interview is conducted concerning the issues in preparation
for question formulation.
The examiner will explain the Polygraph examination records simultaneous three
of the their physiological responses: respiration (breathing); cardio,(blood volume
and heart rate) and the galvanic skin response (conductivity/perspiration).
Questions formulation is conducted.
A short acquaintance examination is conducted to ascertain if all of the
examinees physiological responses are going to be accurately recorded during
At this time the questions that were formulated earlier is reviewed with the examinee
There are no surprises on a polygraph examination.
Three charts will be run using the same questions. After which the examination
will be scored. The examinee will know the results before leaving the office.
Deception Indicated - No Deception Indicated - Inconclusive One of these will be
the final analysis of the examination.
If a report is requested of the final analysis one will be prepared within two
working days of the examination. It will either be mailed or e-mailed at the request
of the examinee
How to choose a certified and experienced Polygraph examiner?
First, make sure the examiner is licensed and certified by an accredited
Polygraph Association. The American Polygraph Association is
the only accrediting organization that maintains the schools certification.
A certified examiner is one who has graduated from an accredited school
maintaining a minimum of 80% grade point average, and who continues his
training for one year under supervision where in his examinations are inspected
and graded for quality control.
Depending on the type of examination you want to be administered, check his experience
and certification in that field. You do not want an examiner who has tested sexual
Issues for the last few years when you need an examination on a twelve year old
family member on allegations of stealing money from a purse at a family reunion.
Make sure he has continued to stay informed of the Technology changes by
attending advanced training programs.
Look for professional affiliations and memberships in State and National Associations
that set professional standards as well as a required number of continued education hours.
The following are some of the most commonly asked questions by persons taking polygraph examinations.
the answers to these questions may give you a better understanind of the polygraph instrument, the procedure
and the purpose of the test itself.
If you wish to ask any additional questions before your test, please do so. the examinier will answer them for you or obtain the answer for you, if it is possible.
What does the polygraph instrument record?
The polygrph instrument recores respiration, pulse rate and relative blood pressure changes and galvanic skin response
The instrument does not ring a bell or flash a light when a lie is told, but instead records changes in a person's body at the
time the prepared questions are asked.
Will I get an electric shock or be injured in any way from the test?
No, the tests will not injure you in any way. there are no electric shocks whatsoever. The only sensation involves the
pressurization of the blood pressure cuff around your arm.
How long does the polygraph examination take?
The entire polygraph examination will last at least one and one half hours. During the first portion, you will be
interviewed and the test questions will be prepared with you and read to you. After the interviewed and the tests lasting
3-5 minutes each will be run. The same questions will be repeated severa times to eliminate any possibility of the
accidental responses. After each rest, the iunstrument will be stopped to give you a chance to relax and ask any
questions you may have.
Will the questions be read to me befgore the test?
Yes, each question that is asked on the test will be read to you word for word and explained to you before the test.
When you are satisfied with the questions and can answer them either "Yes" or "no", the test will begin. You can be
assured there will be no surprise or trick questions in the test. the only questions that will be asked are those that
have been reviewed with you before the test.
Will my nervouseness cause me to fail the tests even though I am telling
No. We expect every person tested to be nervous to a certain extent and we can clearly identify those nervious
patterns. Nervousness is indicated by certaibn physicological recordings that a competent polygraph examiner can
rreadily identify. these recordings will not be confused as lies by your examiner.
If I have high blood presure, will that make a difference?
High blood pressure will not cause an error in the test results; high blood pressure will not mislead the examiner into
believing you are lying if in fact you are telling the truth. However, if you have been under treatment for a heart
condition or a breathing problem or any emotional factions, be sure to advise the examiner beforehead. If necessary and
with your permission, your doctor may be consulted and a proper release obtained.
Can I be forced to take a polygraph (lie detector) test?
No. The poloygraph (lie-detector) is a physiological recording and in the order to function effectively the subject
taking the test must offer resaonable cooperation and display no indications of trying to defeat the process.
If the subject reasonably answers the preliminary inquiries before the test and answers"Yes" and "No" to the test
questions asked, that is considered sufficient cooperation to sucessfully complete the test.
Will I know the results of my polygraph test?
Yes, the examiners who are members of the American Polygraph Association will readily comply to your request for
The polygraph *lie detector) is admissible as court evidence in certain situations. Generally, however, the polygraph
is not admisible as evidence over the objection of the opposing counsel. Polygraph tests may be used by certain judges
to evalute sentence conditions, probation and parole revocations and certain trail considerations.
I heard alot of embarrassing personal questions are asked on this test?
Embarrassing questions, such as those relating to your personal sex life, have no place in a polygraph (lie detector)
test unless the investigation relates to a sex offense. Then, in order to complete the test, questions relating to
sex may be asked. It has been explained previously that surprise questions of any kind are not tolerated in a polygraph
(lie detector) test. If a question has not been read and discussed with you beforehand, it will not be asked on the test.
In addition, any question you object to will be altered to your approval or omitted entirely.
The polygraph test is subject to personal bias by the examiner?
Personal bias by the examiner is impossible with a reputable examiner in that he is required to keep a permanent
record of your case and your chart responses which are open to scrutiny for authorized review. The american Polygraph
Association may be contacted for some relief if you have any valid complaint of examiner bias. Be sure to ensure the
examiner is llicensed or certified as applicable in the area where the examination is administered.
The polygraph (lie detector) is not accurate. Why should I chance taking such a test?
The polygraph (lie detector) has proven to be up to 95% accurate, a figure much higher than most or scientific
What about the 5%, are they error?
Up to 5% of the tests may be termed inconclusive and no decision is offered which does not help or hender the subject.
I feel it is an invation of my privacy if I take a lie detector test?
If you orally agree to be examined about a particular issue and then the questions are read and discussed with you before
the test, how can the lie detector test be termed an invasion of privacy? Usually, you are asked to sign a release which
indicates your consent to taking the test. You can elect to terminate thee testing at anytime the procedure is not
being properly administered to you.
The polygraph is one of the finest modern means of investigation and by its application cases are solved quickly with
the leasst amount of error. If you are telling the truth, the test will substatiate your statement. Worngdoings, when
they affect others is no longer a private matter and when investigated, not an invations of privacy.
What if I have "something else" on my mind, will that show up on the test?
If the "something else" has nothing to do with thte issue, it will not appear as an untruthful reaction on you polygraph
records. the questions reported are only those related to the matter under investigation and not to unrelated matters.
If you feel inclined to tell the examiner this "outside troubling matter" do so, but as a special precaution, obtain the
examiner's promise that the disclosure of this information is a secret and you request that the matter be held in
strict confidence. The examiner will comply with your wishes. The examiner does not wish to enter into your
personal problems since they tend to complicate the polygraph examination.
I feel guilty by taking a polygraph (lie detactor) test?
Why? More than 70% of the persons who take our lie detector tests are proven truthful and fewer than 20% are
found to be lying. The polygraph (lie detector) tests is a truth verifier and therefore a very important aid in the
"Serving Missouri and St. Louis with Honesty and Integrity"
(314) 706- 7087