Options for inexpensive polygraph tests include using online tests, buying polygraph software, buying a polygraph machine, opting for a voice test and negotiating with professional polygraph administrators, according to The Law Dictionary. Tests administered by trained professionals costing hundreds of dollars produce the most accurate results in contrast to the less-expensive methods, in which untrained interpretations of tests tend to be less dependable, as of 2016.
Although the results are dubious, some websites offer free or inexpensive online polygraph tests, notes The Law Dictionary. One free online test instructs the person administering the test to ask a question and then observe the test subject for one minute, according to Calculators Live. The tester answers a series of questions to calculate biological responses, including number of eye blinks, scratching the head, touching the face, avoiding eye contact, and changes in vocal tone or pitch.
Consumers may purchase different types of polygraph software from reputable companies for substantial savings over the fees professionals charge, explains The Law Dictionary. The price can be as little as one-tenth the cost of a professional polygraph exam. Alternatively, the consumer may buy a polygraph machine for less than the cost of an exam. Voice tests can take place over the phone from home, saving subject the time and cost of a trip to take a polygraph test, and the voice test is typically less expensive.