AP Systems LLC

The Birthplace of Acoustic Psychometry®

Introduction to Acoustic Psychometry

Acoustic Psychometry® ("AP") is a computerized method to identify mental states using speech acoustics.

Take a look at the AP image of "Laura, Anxious," for example, and play the recording of her voice.

Laura, Anxious:

Now,play "Laura Composed" and scroll your cursor over the image:

Laura, Composed:

The image of Laura's speech prior to starting treatment, "Laura Anxious," is less integrated than the compact image of her speaking after she has recovered. There is a corresponding reduction of her "fragmentation index", from 65 to 53.

AP images provide a means of rapid, intuitive exploration. AP measurements add precision and further information.

To see how AP images are generated, see "Intro to AP II".

Click here for a concise introduction to AP.

How AP Images Are Generated

AP images represent simultaneous 10 millisecond changes in two acoustic parameters, in this case pitch (horizontal axis) and intensity (vertical axis), computed over the course of an utterance. The colors represent the number, or density, of changes falling within the neighborhoods defined by the little squares. The image is thus read as being three-dimensional.

The most frequent "Core" transformations are distinguished from the less frequent "Border" transformations. Run your cursor over the image at left to see these two acoustic substructures.

The unified AP image of core and border transformations together is shown on the right. Run the video to see how this unified structure is built. The timing on the video is a bit off, but you can still get the idea.


Ron scores high (4.56) on a "conscientiousness" scale, while Rick scores low (2.56). On AP measures Ron maintains the mean of his intensity transformations from core (-5.5) to border (-1.33), while the mean of Rick's intensity changes fall (from -5.0 to -16.4), as if even his speech is acoustically "lazy." Run your cursor over Ron's and Rick's AP images to compare mean intensity deltas while playing their speech. This is reflected in the vertical drop of data point saturation from Rick's core image to his border image, and a constant or rising data point saturation for Ron See this paper for a systematic study of the phenomenon.

Play Ron:

Play Rick:

For an excellent paper that shows both the strengths and weaknesses of the probabilistic paradigm, which differs from the approach of AP, click here.

Here Are Some of the Nice Things People Have Said About Acoustic Psychometry

"AP...provides a flexible and dynamic analysis that is well suited to the complexities of human speech and underlying mental states"

--Ray Kent, Ph.D., Professor Emeritus, University of Wisconsin

"(Dr. Begel) has brought together knowledge from diverse sources such as clinical linguistics and digital signal processing to create a unique window to the mind."

--William Sledge, M.D., George D. and Esther S. Gross Professor and Past Acting Chair, Department of Psychiatry, Yale University School of Medicine

"Brilliant science...So obvious, and yet no one else is thinking this way."

--J.Galen Buckwalter, Ph.D., University of Southern California


The sciences of Biology and Psychology study many of the same phenomena, but they share virtually none of the same concepts or methods. It seems that each field's understanding of the other is primitive at best, rendering the problems they address more difficult to solve.

The phenomenon of human speech, susceptible as it is to study by methods as diverse as brain imaging and psychoanalysis, lies preeminently on the border of the mind and the body. As such it ought to provide a fertile field for integrating the psychological and biological sciences.

Although it will be amusing, and perhaps impressive, to develop various applications for AP in everyday life, this is not our primary mission. Rather, our mission is to develop a method of analysis that both biologists and psychologists, the "hard" and the "soft," understand. Our hope is to create a template for translating at least some of the findings and concepts of one field into the findings and concepts of the other, without losing the essence of either.


Dan Begel was raised in Whitefish Bay, Wisconsin. He received his undergraduate and medical education at Yale University and specialized in psychiatry. At Yale, Dr. Begel studied the classics of behavioral science and the foundations of clinical practice. Among his many extraordinary teachers were Marshall Edelson, Steve Fleck, George Mahl, Malcolm Bowers, and Bob Arnstein. Dr. Begel took special interest in symbolic process, immersing himself in the work of Freud, Piaget, Chomsky, Levi-Strauss, and Roman Jakobson, among others. In recent years, the generous guidance of Ray Kent and Nagu Thogiti have enabled Dr. Begel to acquire a modest understanding of those modern methods for the digital signal processing of speech that provide a technical basis for Acoustic Psychometry.

Prior to his work in Acoustic Psychometry, Dr. Begel pioneered the field of Sport Psychiatry, in which he blended his experience as an athlete and psychiatrist. With his colleague, Bob Burton, he edited and wrote major portions of the first textbook of sport psychiatry and founded the first professional society in that field. A review of his work in the Journal of the American Medical Association stated Dr. Begel's psychodynamic understanding of the athlete is...unparalleled.

Dr. Begel is affiliated with St. John's Medical Center in Santa Monica and Cedars-Sinai Medical Center in Beverly Hills. He is a devoted husband and father and enjoys golf, sports, theater, and jazz music.

Some Possible Applications

  • Identifier of Subject Propensity to Respond to Placebo in Drug Research (IRB Approved Study Currently Underway)
  • Personality Profiler for Online Social Networking, Mobile Phone Apps, Forensic Assessments, et cetera
  • Target Variable Generator for Research in Behavioral Genomics and Brain Imaging
  • Diagnotic Instrument for Clinical Assessment (e.g., Mood Instability, Below)
  • Test for Early Identification of Autism
  • Humanizing Component for Virtual Reality Systems
  • Enhancer of Speech Recognition and Speech Synthesis Systems

  • The covariance of pitch transformations with intensity transformations seems quite susceptible to emotional weather. The two patients, Edna and Florence, represented by the AP images on the left and right, respectively, both presented with symptoms of depression. Edna, whose prevailing moods tended to be stable, responded well to straightforward treatment with an SSRI antidepressant. Florence, whose moods were unstable, responded poorly to treatment with an antidepressant alone and required treatment for Bipolar Depression with mood stabilizers. Acoustically, the covariance of pitch with intensity in Edna's speech remains similar in both prevailing (core) and infrequent (border) transformations, with the data axis going from lower left to upper right {core covariance index = .52 ; border covariance index = .54 ) The core and border covariance axes shifts significantly in the course of Florence's speech, however, reflecting her emotional lability. Her core axis is basically horizonal, while the border axis forms a rough "X"{covariance core = .12, border = .78) You may run you cursor over the images (Edna,left; Florence,right) to show the core and border structures of these two patients while listening to their speech. Play Edna:

    Play Florence:





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    Click here to see the instrument we use in AP, the "Acoustic Psychometer."

    Although the Acoustic Psychometer is not yet compiled as an independent program, please feel free to contact Dan for a demonstration of it online.

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