AVSAPRO is simply the worlds most advanced voice stress detection (VSD) system. So advanced, that we refer to it as Voice Polygraph (VP). The research papers of various government sponsored projects as well as privately funded research confirm that modern VSD systems are as reliable as the traditional biofeedback polygraph system.

AVSAPRO is the only fully automated VSD system. APA validated Question Constructs (templates) and Question Libraries are built in. Cadence between Question Onset and Subject Response is controlled by AVSAPRO. Homeostasis recovery period is controlled. AVSAPRO fully integrates with all MS Windows platforms. Filing may be numeric, alpha or alphanumeric, into any directory as selected. Multiple filing and recall options are available. Simplified results reports are produced within seconds. We provide analog headset microphones which match the frequency response of human voice.

AVSAPRO rotates the CQ/RQ sequence automatically from chart to chart. Users may choose from templates such as IZCT, UTAH, USAF-MGQT, REID MGQT and other popular screening constructs, or even design their own templates for research or other purposes. The crime specific libraries offer up instant questions, which may be easily edited. Templates may be stored in the program FILES utility, or elsewhere. All files and tests may be stored in AVSAPRO, a Windows directory, or on removable drives.

AVSAPRO utilises a neural network database that has been trained with some 6000 known solution voice waves. Scoring is therefore not indiscriminate, but is the result of decades of testing by DOD experts and known solutions. AVSAPRO is the only VSD system worldwide that utilises AI technology.

For further details please visit http://www.avsapro.com

AVSAPRO Fundamentals

Various VSD software programs offer a graphic representation derived from that obtained on the Polygraph.

AVSAPRO uses sound recordings made in WAV format, to 11,025 Hz, 8bits.

Voice sounds are filtered by retaining low frequencies. Modulation is added in order to bring out the low frequency oscillations.

Some VSD software programs use a theory introduced by the British physiologist Olaf Lippold, 1957, by extracting the low frequency of about 8 to 12 Hz and deducing a value of stress thereon.

Understandably, it’s not too difficult to compute the frequency for the wave displayed in Image 1, but it becomes much more complex for graphs as displayed in image 2.



AVSAPRO uses a new technique for calculating the value of stress, to score voice waves and not one based on direct, manual analysis of the micro-tremor.

AVSAPRO software uses a knowledge base collected from several VSD experts. Approximately 6,000 pre-scored voice signatures are retained in a neural network database.

A totally independent scoring exercise was conducted by VSD experts. At the culmination of the project it was notable that 80% of the results presented only 5% difference on the estimated values of stress, which provides a consistent and reliable basis for the techniques used by AVSAPRO Software.

The technique consists in training a neural network with 6,000 phonemes (distinct verbal responses) from interrogations. The voice samples are processed to obtain the graphs as per Image 1 and Image 2 above.

These graphs were digitized to provide a basic set for training the neural network. The training of the neural network generates a file of weights that are at the heart of the network processor. Some parameters are used to adjust the neural network; i.e. the number of neurons in input, the threshold, the desired error (1%).

A fundamental property of the neural network is its capability to produce a reliable result when we enter a voice graph for which it has not been trained. When we submit a graph for which it was not trained, it will produce a result with the specified error (1%). Other external errors may influence the overall error rate  e.g.examiner training and skillset.

AVSAPRO extracts phonemes in real time and digitizes waves. Charts are submitted to the network and thereafter the results are displayed. Another interesting neural network property is that there is no need to calculate complicated mathematical formulas in order to extract frequencies of micro tremors. The neural processor teaches itself how to deduct the outcome on the basis of data provided.

It is totally free from the assumption 11-12Hz for low stress and <8->4HZ for the presence of stress. Our certainty is the know-how of human experts who have conducted thousands of successful vsa examinations, together with known solution outcomes.

AVSAPRO software can calculate up to 20 estimates of stress per second on a standard PC. Charted tests (validated protocols) are scored within 2 seconds. Exam scores (average of the tests conducted) are displayed instantly at the culmination of the last test chart. AVSAPRO currently provides THREE commercial versions :

  • Version 2,0 : For structured DOD interview examinations + all auto features. Manual operation is still retained.
  • Version 1,7 : For free flow, real time narrative screening. Easy to follow graphics for operators processing high volumes of subjects. Two stress levels engines are provided.
  • Version 100; which combines the two previous versions and includes built-in question libraries and easy Build-A-Test feature with crime specific libraries. Also specific libraries for Pre-Employment screening and Periodic screening.

AVSAPRO may be used easily and successfully over smart phones. A 1:2 RCA splitter, a RCA flylead + mobile headphone is required.

Both programs feature Autogain to compensate for low input volumes. AVSAPRO is fully compatible with all versions of Microsoft Windows OS.

Versions for Android and Mac are currently under construction.




  • The only truly automated, VSD program providing real time results.. AVSAPRO is in no way to be confused with LVA.
  • AVSAPRO auto-scores Validated PDD test protocols (Zone of Control and Screenings for Pre-Employment and Periodic screening, or free narrative)
  • Examiner may score captured response graphics manually
  • Auto Tabbing of CQ’s and RQ’s
  • Auto Scoring of individual tests
  • Auto Scoring of entire examinations (multiple test charts)
  • Auto Rotation of RQ’s
  • Auto Control of Cadence –Audible Answer Cue (Onset Delay of FOF response)
  • Auto Assignment of SV (stress value) to every captured word during interview narrative. Recording time frame exceeds five minutes per file. Unlimited file capacity.
  • Auto, real-time check and display of incoming signal volume
  • Fully Integrated with ALL MS Windows platforms; MS Word / Explorer / Notepad etc
  • AVSAPRO files tests in alphabetical sequence for individuals. Batch files for corporate and / or regular clients may be created in AVSA Files or other Windows applications.
  • Fully integrated with MS Windows platforms.
  • AVSAPRO utilizes neural network processor power.
  • Known Solution Database. The expertise of VSD experts spanning 30 years
  • AVSAPRO training is presented by selected, thoroughly trained professionals.
  • AVSAPRO is distributed by an internationally certified PDD examiner, recognized DOD professional and author on PDD Techniques and Technologies.

AVSAPRO is the most advanced VSD program available worldwide.
AVSAPRO is written by Alpes Software. The only VSD software ever validated was also written by Alpes. (Refer to AFRL – ROME study )


  • Specifically designed to conduct real-time narrative screening interviews, covert or overt. Provides instant, easy to follow vertical colour bars, arrays and % linear graphs to monitor DI / NDI trends and transitions.
  • Designed to provide real time results from telephone discussions.
  • Ideal for call centre operations and high security environments

Both AVSAPRO 1,7 & 2,0 are provided with a single licence purchase.


POLYVSA Institute of Training