Audio Forensics: Voice Risk Analysis Fails Practical Trial

Voice Risk Analysis (VRA) has always been viewed skeptically by many in the speech field. This technique takes Voice Stress Analysis - i.e. analyzing speech for microtremors and possibly other indicators of nervousness, anxiety, and general stress - and applies it to a real world problem. As far as the science of strict voice stress analysis goes, it is believable to me based on my own observations. I have seen that many people can exhibit audible stress in their voices when under emotional or physical stress.  As an experiment, try listening to someone on the phone when they are climbing a set of stairs rapidly and you should notice a difference!

Voice Risk Analysis takes this concept and extends it to the automated detection of deception (lying) over telephone calls.  Is this completely unbelievable on the face of it? Not completely - you may have occasionally encountered people who sound nervous when trying to lie.  However, pricey products have been sold based on extrapolating this a step further to claim that simply by analyzing telephone speech to a finer level of detail (e.g. looking for microtremors) one can detect stress and even lying in the general population.

The Guardian (a center-left news organization in the UK) has a news article on the results of practical trials conducted by the British government using a commercial VRA system to attempt to catch people lying in telephone interviews regarding government-funded benefits. After analyzing the results from 45,000 calls, the bottom line was that the system did not provide enough value to justify its cost.  Given the history of VRA and my own understanding of speech science, I am not surprised at all by the findings.  Hopefully, as a matter of public policy, this will put an end to government purchases of VRA technology until such a time as it is proven by peer-reviewed studies to work for the application(s) it is intended for.

Forensic Education: Upcoming Audio Forensics Workshop

I would like to pass along the following announcement:

The National Center for Media Forensics at the University of Colorado Denver will be holding an Audio Forensics Workshop December 13-15, 2010 in Denver, CO.  This course is an introduction to digital audio, acoustics, audio evidence admissibility, and recorded speech enhancement.  It is the perfect experience for those new to the field, practitioners needing to review forensic audio theory and practice, or those accustomed to working with other types of digital and multimedia evidence.  Course topics include:

·       Introduction to Media Forensics

-        Overview and principles in Media Forensics

-        Admissibility of audio evidence

 

·       Foundations for Forensic Audio Enhancement

-        Sound and acoustics

-        Audio recording and playback

-        Digitization of sound

-        Signal processing and enhancement algorithms

·       Demonstration and Practice

-        Digital evidence seizure and acquisition

-        Enhancement practice

-        Notes and report writing

-        Preparation of enhanced material

 

The course will be co-taught by Dr. Catalin Grigoras and Jeff M. Smith.  The cost for this class is $850 and graduate level university credit will be given upon completion.  

Science Education: The Listen Project

My local newspaper (Charleston's Post and Courier) had a blurb in the comics section this week that mentioned a good resource for kids (at heart) to learn about audio. It is the Listen Project and can be found on the Exploratorium's website.  It seems to live up to its tag line of "Explore the art and science of listening".  I highly recommend it.

To give credit where credit is due - the project is funded by the National Science Foundation, the Gordon and Betty Moore Foundation, The Bernard Osher Foundation, and the National Endowment for the Arts.

Enjoy!

Science Education: Summer Science Programs in Forensics

The South Carolina Governor's School for Science and Mathematics (USA) runs its Summer Science Programs (SSP) every summer. SSP is a residential summer camp for rising 8th, 9th and 10th graders. Both in-state and out-of-state students are accepted.


I'll be teaching two, one-week runnings of my course, A Mathematical Tour of Forensic Science, again this year.  In addition, Dr. Sid Parrish will be teaching his ever popular CSI (Crime Scene Investigation) course.  For those who, for some unimaginable reason, might want to take courses in subjects unrelated to forensics, there are a large number of offerings (Lego Robotics, Great Experiments in Physics, and more).  If you are interested, you can find out more on their website. I hope to see you there!

Education: Yenka Light and Sound modeling software

I've been using Falstad's freeware Java applets for teaching acoustics and oscillation concepts in the classroom for years now. I recently decided to give Crocodile Clips' Yenka Light and Sound modeling software a try after some of my own children enjoyed using it in school. At first it was to take advantage of the free license for home use (yes, FREE). Now, however, I'm going to use it in classes thanks to the numerous models already built-in and even more content online. My favorite built-in model so far is "Speed of Sound" - which lets you add other media, such as vacuum, water, and wood, and see how the speed of sound changes and then interacts with the sound wave in air, assuming it exits the extra media at all - very cool!

Not to leave optics out, there are informative models for angles of reflection, refraction, mirrors, lenses, telescopes, and more. For instance, to show that the angle of incidence equals the angle of reflection, the student drags two protractors into the workspace and measures both angles as the (virtual) beam of light bounces off the mirror. Simple, but effective. Many more sophisticated models are available too, plus you can build your own and save them for later use (as an educator, I like that).

Yenka also covers more than the physics of sound and light - mathematics, chemistry, computers, electronics, and other packages are also available. I've tried the chemistry package with my boys. Being boys, they were particularly pleased with being able to experiment with (virtual) dangerous substances after having to suffer through the kid-safe chemistry sets sold in stores these days.

Crocodile Clips is based in the UK, so American and other visitors to their website may not understand the references to terminology used in the British education system. Luckily, the laws of physics do not change as a result of the software leaving the UK! Yenka is a free download for students to use at home. Use outside of the home requires buying a license, of course. Finally, it works on Mac and Windows operating systems.

Enjoy!

Image Forensics: New blog - Forensic Photoshop

There is a "new" (i.e. started this year) forensic blog that goes into some of the nitty gritty details of image forensics. Forensic Photoshop is penned by Jim Hoerricks, who is an experienced practitioner in the field. I've found his posts to be both very interesting and current. Enjoy!

Image Forensics: New Best Practices Document for Forensic Video Analysis

The committer members over at SWGIT (Scientific Working Group on Imaging Technology) have been very busy lately. Following the recent release of two new sections for review, they have now added another - Best Practices for Forensic Video Analysis. It and other documents can be found be found by following this link.

Image Forensics: Good Practices

The Scientific Working Group on Imaging Technology (SWGIT) has released drafts of two new "good practices" documents for image forensics, titled "Best Practices for Forensic Photographic Comparison" and "Digital Imaging Technology Issues for the Courts".

These drafts, along with previously released good practices documents from SWGIT and other organizations, can be found on the IAI (International Association of Identification) website at this link.

(Hat Tip: MB)

Forensic Education: Courses for young and old who are interested in forensic audio and video

I've got two announcements regarding forensic education to pass along.

First off, the Department of Justice (USA) is funding Professor Rich Sanders, of the University of Colorado, Denver, to establish a new National Center for Audio/Video Forensics. The full university press release can be found here. It is scheduled to be up and running in the fall of 2009.

Second, the South Carolina Governor's School for Science and Mathematics (USA) runs its popular Summer Science Programs (SSP) every summer. SSP is a residential summer camp for rising 8th, 9th and 10th graders from across the state. The reason I mention it here is that I have been asked to teach two one-week runnings of a new course entitled A Mathematical Tour of Forensic Science. If you are interested, you can find out more on their website.

Update: I am informed by the director of the SSP that students from outside of South Carolina are also very welcome to participate.