Sound and Light Reflections

Science Education: Summer Science Programs in Forensics

2011-05-15T14:38:00.000-04:00

It is that time of year again for students and parents - time for signing students up for summer camps!

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.

As usual, I'll be teaching two, one-week runnings of my course, Applied Forensic Science (formerly: 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 Classical Physics, and more). If you are interested, you can find out more on their website. I hope to see you there!

Human Auditory System: Musical training helps students and the elderly alike

2011-05-15T14:20:00.001-04:00

Northwestern researchers Alexandra Parbery-Clark, Dana Strait, Samira Anderson, Emily Hittner and Nina Kraus have published a journal article that extends the work being done into advantages that students get from musical training and experience to the elderly. Their work seems to show that life-long musical training improves memory and the ability to understand speech in noisy environments. This makes sense, intuitively. After all, the human auditory system, like the human visual system, relies upon extracting and matching patterns to do its job and the more practice it gets the better job it can do!

Enjoy,
Keith

Education: US Department of State Scholarships for Needed Foreign Languages

2011-02-01T12:29:00.000-05:00

The National Security Language Initiative for Youth (NSLI-Y) program offered by the US Government's Department of State offers merit-based scholarships to US high school students to study particularly needed languages (i.e. Arabic, Mandarin Chinese, Russian, Hindi, Korean, Persian, and Turkish). Applicants who successfully make it through the selection process will be sent abroad for either six-week or one semester long programs. All program related costs (e.g. travel, room, and board) are paid for by the scholarship. More details can be found on their website (link).

(Hat Tip: Government Video)

Human Speech System: North American English Dialects

2011-01-04T20:26:00.000-05:00

I don't even know this gentleman, but I confess that I have to like him just based on his introduction to this excellent website:

This is just a little hobby of mine, that I thought might be interesting to a lot of people. Some people collect stamps. Others collect coins. I collect dialects. Please let me know what you think of this page. - Rick Aschmann

See what I mean?

Mr. Aschmann has put together a collection of North American accents based on pronunciation. It is fascinating...

His work reminds me of an incident from many years ago, back during the Cold War. I was attending a dinner party at a US Embassy and was unexpectedly, but playfully, escorted to stand in front of a young woman who was with an Italian film company. I was asked by the onlookers to say just a few words in a sentence and to stop. Once I had done so, everyone turned to look expectantly at the young woman, who, after a pregnant pause, said something along the lines of "hmmm.... American" (which brought groans from the onlookers), "south eastern" (yielding just a few groans), "South Carolina" (serious looks), "Darlington County" (at my nod of affirmation, this led to gasps and dropped jaws). It turned out that she was the speech consultant to the film and her credits included coaching Mel Gibson (the Aussie from the Mad Max and other mainstream film series) and the New York African-Americans who needed to sound like Southerners in the movie "The Color Purple".

Enjoy!

(Hat tip: The Economist, center left, UK, news magazine)

Forensic Audio: An Introduction

2010-12-30T06:36:00.000-05:00

A colleague and former student of mine, Detective Phil Manchester (UK), wrote an excellent article earlier this year titled "An Introduction to Forensic Audio". It appeared in the British audiophile magazine Sound on Sound. I highly recommend reading this short overview of audio forensics.

Enjoy!

Crime Scene Investigation: Photographic Portfolio

2010-12-29T13:57:00.000-05:00

A former forensic crime lab technician turned professional photographer named Angela Strassheim has used her fascination with crime scenes to create a photographic portfolio. For the portfolio, she visited dozens of former crime scenes and photographed them using a combination of low light, long exposure times, black and white film, and a chemical reagent used to highlight blood stains. The results are fascinating and you can see them here.

Music: The Humanthesizer

2010-11-22T14:02:00.000-05:00

What can a group of engineers and a musician do with a computer, a sound card, a bunch of dancers, a singer, and a bucket of conductive paint? Create the Humanthesizer!

A bit of fun for a Monday morning - enjoy!

PS. I recommend watching "The making of..." clip first and then the actual performance.
PPS. A "boffin" is a scientist/engineer in British slang.

(Hat tip - Thanks Robert C!)

Audio Forensics: Voice Risk Analysis Fails Practical Trial

2010-11-22T13:00:00.000-05:00

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.

Photography: Preserving old photos and documents

2010-11-19T13:00:00.000-05:00

One of my favorite websites, lifehacker, has an article based around material by Lynda Schmitz Fuhrig, the electronic archivist for the Smithsonian Institution Archives, on how to best preserve old photographs and other documents. This topic is very important for forensic examiners and the legal system in general as, at least in the USA, we have to preserve evidence for at least 25 years in case there is ever a re-trial.

For information about the long term care and handling of DVDs and CDs, I highly recommend the National Institute of Science and Technologies guide to the subject, available in PDF format (size = 1.24MB) at the following link.

Enjoy!
Keith

Forensic Education: Upcoming Audio Forensics Workshop

2010-10-11T12:20:00.000-04:00

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.

Human Visual System: Gene identified that causes short sightedness

2010-09-14T08:28:00.000-04:00

The BBC (center-left news, United Kingdom) reports on research at King's College London that has tentatively identified a gene that causes myopia, commonly known as short-sightedness. For those who confuse short and long sightedness, just remember that they are what their names say - you see objects better at short distances when short-sighted and you see objects better at long distances when long-sighted. The article is well written and has graphics to explain the condition.

Human Speech System: Woman's migraine causes French accent

2010-09-14T08:23:00.000-04:00

A woman in the United Kingdom is suffering from Foreign Accent Syndrome - a rare condition caused by damage to the brain that results in changes to a person's accent. In this case, the woman went from a British accent to a French one. The Guardian (UK, left-wing newspaper) has the story. Fascinating.

Image Forensics: Bad "Photoshopped" Mad Men cover on Rolling Stones

2010-09-14T08:19:00.000-04:00

The title of this post says it all - the writers at Jezebel (a celebrity news for women) wrote about it first. See for yourself.
Enjoy!

Linguistics: Challenge Puzzles

2010-08-30T15:02:00.000-04:00

Here is a fun website with lots of puzzles - from easy to hard - involving linguistics. Enjoy!

(Hat Tip: SiliconValley.com, USA, technology news)

Human Speech System: Test your lip-reading ability

2010-08-26T09:58:00.000-04:00

Speech scientists have long known that seeing individuals can, even unconsciously, use lip-reading to assist in decoding words spoken in a conversation. (Note: lip-reading words spoken randomly, without context, is very difficult). This entertaining and challenging puzzle (link to a Wired on-line article entitled A Classic Back-to-School Lip-Reading Puzzle) will test whether you can match a given list of names to faces in an illustration by lip-reading, given the context that each boy in the illustration is on the verge of pronouncing his name.

Enjoy!

Admin: Apologies and "make up" for light posting

2010-07-30T14:57:00.000-04:00

Hi, All.
It has been a very hectic summer for me (again), but I'm back to blogging (finally).

I offer the following website and comic as a sort of "make up" for my delinquency.

Enjoy!
Keith

(Hat tip to EE Life)

Science Education: The Listen Project

2010-05-17T11:36:00.000-04:00

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

2010-04-05T21:37:00.001-04:00

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!

Science Education: Popular Science Magazine puts entire archive online for free viewing

2010-03-06T05:25:00.000-05:00

As a kid growing up in the USA in the 70's, I spent a lot of time in my local public library reading everything I could get my hands on. When it came to science and technology magazines, I remember reading every single Popular Mechanics, Popular Science, and Scientific American as soon as it came in. Of course, a lot of what was in Scientific American was written above my academic level, but with each issue I read I got a little further into each article before I was lost- over time I gave myself a pretty good science education that way. (Aside: of course, that was before Scientific American became so politicized, but I can expound upon the politicization of science and science journalism another day...).

This trip down Memory Lane has a pleasant destination - Popular Science Magazine has put its entire archive of back issues - complete with period advertisements- online for free viewing. The archive is even searchable using Google's technology. Very cool, in a geeky sort of way (yes, I was a geek before geeks became cool).

Enjoy!

Speech Recognition: Men harder to understand than women

2010-03-04T05:07:00.000-05:00

Researchers at Stanford University (USA) and the University of Edinburgh (UK) have tested various automatic speech recognition (ASR) systems and found that in general they have a more difficult time recognizing speech from males than females. One of the causes mentioned by the researchers was that the men tended to use fillers such as "emm" more often.

I should point out that the tests were conducted using recordings of telephone calls. This is important because the type of "channel" the audio is being carried over makes a significant difference to a computer-based speech recognition system.

The work was sponsored by the US Office of Naval Research.

For a quick overview of the research, you can read the BBC (center-left news media, UK) article here.

Enjoy!

Human Auditory System: Audiences hate modern classical music because their brains can not cope

2010-02-23T14:53:00.000-05:00

I guess there is a scientific reason "modern" classical music sounds so awful to my ear after all! The Daily Telegraph (center-right newspaper, UK) has the story.

Human Visual System: Caucasians and Asians recognize faces and expressions differently

2010-02-06T14:26:00.000-05:00

World Science (an online science news site) summarizes work by researchers at the University of Montreal (Canada) into how Asians and Caucasians differ in recognizing faces and facial expressions. Eye tracking cameras were used to monitor where the subjects were gazing. Doctoral candidate and researcher Caroline Blais said that

The study confirmed that Caucasians study the triangle of the eyes and mouth, while Asians focus on the nose..

In a separate study, she also tested how recognition of facial expressions differed between the two ethnic groups. It turned out that Asians were not as accurate at recognizing emotions that required observing the mouth, such as fear, disgust, and anger.

The two studies were published in the journals Current Biology and PLoS One.

Acoustics: Visualizing whale calls as art

2010-02-01T16:24:00.000-05:00

NewScientist (science magazine, UK) has a fascinating set of images from Mark Fischer, who uses artistically manipulated wavelet transforms of the calls of marine mammals to create stunning artwork.
Enjoy!

Science and Math: Another round-up of interesting links

2010-01-18T15:40:00.000-05:00

I have been having difficulty finding enough time to write my normal analysis and commentary on the information I have come across. Therefore, in order to not fall any further behind in getting interesting things out to you, I'm going to once again resort to listing the links.

With apologies, here they are:

US Judge rules that computerized voice stress analysis can be used to monitor offenders (note: I've blogged previously about how detecting stress is NOT the same as detecting a lie)

Mathematicians: An Outer View of an Inner World

NASA Interstellar Boundary Explorer Mission

Forensic Audio overview article

Mysterious spiral lights
(solution: failed Russian missile launch)

Victorian Infographics

Virtual tours you don't want to miss

Saturn at equinox

The secret life of chaos

Enjoy!

Acoustics: Shattering glass with sound

2009-12-13T14:46:00.000-05:00

I really enjoy Make Magazine (USA) for their many contributions to open source hardware development, but that is not the subject of this post. Instead, I'd like to point you to an excellent video they have up on their site from the MIT Department of Physics on breaking a wine glass with sound.

Law Enforcement: LRAD used for crowd control

2009-12-13T14:29:00.000-05:00

The LRAD (Long Range Acoustic Device) was used for crowd control during a G-20 meeting in Pittsburg, USA in September 2009, according to this report. For background on LRAD, see my previous post.

Human Auditory System: Learn echolocation

2009-12-13T14:23:00.001-05:00

I came across (yet) another article on learning echolocation, this time by Wired (USA, popular technology magazine). It is worth a read, if only for the observations, such as getting dry mouth from clicking too much.

For the record, I posted about this topic before to refute the contention that humans are learning to do this for the first time.

Admin: Word verification requirement for comments

2009-11-24T09:53:00.000-05:00

Due to an overly burdensome and increasing amount of spam comments, I have turned on word verification for all submitted comments. I hope that this has not inconvenienced anyone.

Kind Regards,

Keith

Audio Forensics: Signal Processing helps unravel JFK Shooting evidence

2009-11-24T09:48:00.000-05:00

IEEE (The Institute of Electrical and Electronic Engineers) has started a public video section on its web site it calls ieee.tv. I have been a member of IEEE since at least my graduate school days, as are many speech and forensic scientists, so if you are in either one or both of these fields and are not a member, I highly recommend that you check into it. (And in the spirit of full disclosure and in the hopes of avoiding investigation under who knows what new law is actually now or ever will be on the books about such things on the Internet - no, they didn't pay me to plug them as a professional organization!).

On to the subject of this post: ieee.tv has a fascinating video clip on the gunshot analysis performed by various experts on the recordings JFK assassination.

Hat Tip: Thanks Alex!

Human Auditory System: Foreign subtitles improve speech perception

2009-11-13T19:55:00.003-05:00

Want to improve your ability to comprehend a second spoken language? One way is to watch foreign films and read the foreign language subtitles - not the English ones. Eurekalert reports on a recent study.

Human Auditory System: Newborn babies cry with mother's accent

2009-11-13T19:49:00.004-05:00

MedGadget reports on a study by French and German scientists on accent that a newborn uses - conclusion: its mother's. It is well known that a person's hearing system begins functioning while still forming in the womb. I find it fascinating that it is also "training" the speech part of the system at the same time and that the interplay works so soon after birth.

Audio Forensics: Pro Tools Snow Leopard Pre-Release

2009-11-01T20:48:00.003-05:00

I don't use Pro Tools myself, but many audio forensics professionals do, so here is a breaking news item...

From Hitsquad Musician's News:

Pro Tools Prerelease now available for Mac OS X Snow Leopard
Avid/Digidesign is pleased to announce the immediate availability of a prerelease version of Pro Tools software that provides expanded Mac OS X 10.6.x Snow Leopard compatibility to Pro Tools 8 users.

Audio Forensics: Speech quality versus intelligibility

2009-10-23T21:28:00.002-04:00

Engineering Technology Magazine (Institute of Engineering and Technology, UK) has a well written article concerning research by CLEAR (Center for Law Enforcement Audio Research) concerning the effect of noise reduction on intelligibility of evidentiary recordings and other audio in law enforcement situations.

... most speech-enhancement techniques improve sound quality at the expense of intelligibility, particularly when the signal-to-noise ratio (SNR) is very low. Closely related as they are, speech quality and intelligibility are not identical.

This is a classic trap that is easy for a novice to fall into.

Read it all.

(Hat tip: RH)

Human Hearing System: When an ear witness decides the case

2009-09-30T20:03:00.002-04:00

The New York Times (USA) has an excellent article on human speech and hearing and how the vision system interacts with hearing.

Enjoy!

Filtering: Video clip explains Auto-Tune software

2009-09-30T15:19:00.002-04:00

Nova's ScienceNOW by PBS (Public Broadcasting Service, USA) has an informative video clip on Andy Hildebrand's pitch-correction software called Auto-Tune. This audio filtering technology is used by professionals to correct mis-sung notes both in the studio and during live performances. It has been compared to Photoshop for voices.

Enjoy!

Audio: Laser microphone patented

2009-09-26T15:15:00.002-04:00

Wired.com reports on a new type of microphone designed and patented by David Schwartz. The principle behind the design involves a laser beam measuring the vibrations of smoke particles in a tube as they are deflected by sound. There are two interesting video clips on the Wired.com page - one showing a demonstration of the second prototype and the other showing the components of the device.

Enjoy!

Biometrics: FBI to migrate to multi-modal biometrics

2009-09-26T15:10:00.003-04:00

COMPUTERWORLD reports on the FBI (Federal Bureau of Investigation, USA) announcement at the Biometric Consortium Conference that it will migrate from its IAFIS fingerprint database to a new multi-modal biometric database that will include DNA records, 3-D facial imaging, palm prints, and voice scans.

Image Forensics: Seeing is NOT believing

2009-08-29T19:57:00.004-04:00

Spectrum Magazine (by the Institute of Electrical and Electronic Engineers, or IEEE, USA) has an excellent overview article on detecting tampering in digital photographs by Professor Hany Farid (Dartmouth College, USA).

Enjoy!

Human Auditory System: The Power of the Pentatonic Scale

2009-08-03T12:00:00.002-04:00

Here is a link to a video of Bobby McFerrin (a famous jazz and a cappella musician) demonstrating the power of the pentatonic music scale at the World Science Festival 2009. Short and fascinating!

Enjoy!

Admin: Posting will be light

2009-07-24T12:05:00.001-04:00

Due to a continuing heavy travel schedule, posting will be light for a while.

Education: Yenka Light and Sound modeling software

2009-06-12T11:15:00.005-04:00

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!

Forensic Linguistics: Identify the language of a text

2009-04-29T11:22:00.005-04:00

LangID is a new website that will identify the language of any text you can paste into its webpage or upload/tweet/email them with. This free service is based on the Google Ajax API (Application Programmer Interface) and currently identifies around 85 (human) languages with more being added. A list of the languages that it can identify can be found at this link.

(Hat tip: Good Morning Silicon Valley)

Admin: Summer Science Program in Forensics

2009-04-16T22:27:00.002-04:00

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. I'll be teaching two, one-week runnings of my course, A Mathematical Tour of Forensic Science, again this year. If you are interested, you can find out more on their website. I hope to see you there.

Admin: Posting will be light

2009-03-12T06:40:00.001-04:00

Due to a continuing, heavy travel schedule, posting will be light for a bit longer.

Forensics: US National Academy of Sciences report is released

2009-02-19T06:12:00.003-05:00

DNA evidence was the pebble in the pond, so to speak, for elevating the "science" in "forensic science" - the scientific rigor that has accompanied this new discipline of forensic science continues to ripple through all of the forensic disciplines and our legal system. Of course, DNA evidence was not the only motivating factor, but I do contend that it was the most significant and that the mindset that accompanied its introduction also carried over the other disciplines.

The latest ripple was the release yesterday of a report by the US National Academy of Sciences titled "Strengthening Forensic Science in the United States: A Path Forward". You can read it online or pre-order a print copy at this link.

One should keep in mind while listening to or reading press accounts of this report something that Robert Mueller (physicist, USA) once said, and I'll paraphrase: "Everything reported in broadcast or print media is generally correct, except, that is, for what they report on things that you are actually well versed in, which they invariably get wrong." Such will likely be the case with reporting on this subject.

That being said, how I am interpreting the early press accounts of the report is that this report is another step in this process of bringing the scientific rigor applied to the introduction of DNA evidence into our legal system to all of the disciplines that were already here. In my opinion, this is a worthwhile endeavor. However, we must all be wise enough to understand that we are humans and that any system we create will not be perfect, but if we design the system correctly then mechanisms will be included to minimize and weed out these natural errors while also minimizing the adverse affects on the ability of the system to perform its intended purpose.

Phonetics: The Sounds of American English

2009-02-18T07:37:00.003-05:00

Check out this educational page on the Sounds of American English from the University of Iowa (USA) - complete with cut-away animations of what is happening in the vocal tract and videos of the face during articulation. My wife is probably tired of hearing me point out over the years that this is exactly what is missing from educational software for learning foreign languages. Learning to properly articulate a sound element (phoneme) is so much easier if you know what the articulators (i.e. lips, tongue, jaw) are doing! Well done.

(Hat tip: Good Morning Silicon Valley)

Photography: Automatic panning device for gigabit images

2009-02-08T07:44:00.003-05:00

Engadget profiled the GigaPan Epic some time ago. The Epic is a robotic camera mount that holds your point-and-shoot digital camera and then automatically pans the visual scene, taking picture after picture (up to thousands, according to the manufacturer). Software is included that then automatically stiches the individual images into a single digital panoramic image. Very cool. The inventor used it at the recent inauguration to capture a panorama of the mall. Many more images can be found at a community page devoted to these images. Here is a link to the product page with more details (and the sales price).

Why would anyone need so many pixels in an image? Over the Christmas holidays, the pundits were telling us that no one needs more than, say, 6 megapixels in a camera. Two examples where more pixels are needed include when one needs to zoom in to get small details or when one requires very wide angle shots with good resolution (i.e. which is hard to do with a fisheye lens or a dome mirror).

A potential forensics application is crime scene photography, thanks not only to its functionality, but also its modest cost and compatibility with a wide range of digital cameras.

Enjoy!

Image Restoration: iMovie Stabilization feature

2009-02-08T07:25:00.002-05:00

Despite the best of intentions, I have not yet been able to get around to testing Apple's new iMovie video stabilization feature for the Mac OS (Operating System). I will, however, whet you appetite with a Macworld review I've come across that gives examples.

Enjoy!

Audio Forensics: Solving a Beatles' chord mystery

2009-01-30T13:31:00.003-05:00

Dalhousie University (Nova Scotia) math professor Jason Brown has apparently solved a musical "who-dunnit" - what was the opening chord of the Beatles' famous Hard Days Night? There was an agreed upon suspect - namely George Harrison - but what was the chord? No one could reproduce it, even knowing what guitars they used in performances.

Enter Professor Brown. The professor used tools well known to forensic audio examiners - an FFT (Fast Fourier Transform) to analyze the spectrum and logic. And what did he deduce? It appears that George Harrision had a little help from someone else - perhaps the Beatles' manager, George Martin - who simultaneously played the chord on a piano! So, in the spirit of the board game Clue (Cluedo, for you Brits), it was George AND George, in the recording studio, with a guitar AND piano. Mystery solved!

Here is an article to read more about it. And another one. Enjoy!

(Hat tip to D.E. - thanks!)

Computer Audio: Latest Audacity beta (1.3.7) is released

2009-01-30T11:59:00.003-05:00

Audacity 1.3.7(beta) is available for download. This release primarily seems to consist of bug fixes, but they do say that they added support for DirectSound, which is a widely-used Windows(R) DirectX API (Application Programmer Interface). Here is the text from their announcement:

Audacity (http://audacity.sourceforge.net/) is a fast multi-track audio editor and recorder for Windows, Mac, and Linux/Unix.

The Audacity Team is pleased to announce the release of Audacity 1.3.7 (beta) for Windows, Mac and Linux/Unix. This is primarily a bug-fix release to significantly improve stability and usability, especially on Mac OS X, but includes some new features too.

Cross-Platform Bug Fixes include:

* Muting/soloing caused incorrect channel results in exported stereo files
* Fixes for Nyquist effects, Compressor and Noise Removal
* Fixed Export as WAV could be corrupted if overwriting to same file, and Export Multiple to uncompressed formats only produced 16-bit WAV
* MP3 and WMA now export correctly with all supported metadata

Platform-specific Bug Fixes include:
* Windows Vista: crash opening Preferences
* Mac OS X and Linux: fixes for spurious clipping, label typing, no shortcuts after running effects, and project rate when importing files
* Mac OS X only: fixes for inactive or corrupted menus and hidden dialogues, portable settings, and Command and Control shortcuts. Also FFmpeg installer now available.

New features/other improvements:
* F11 Full Screen mode, high-quality "Sliding Time Scale/Pitch Shift" effect, Audio Contrast Analyzer
* Windows: sound devices can now be opened using the more efficient DirectSound API
* Improved latency correction using fixed correction value

See http://audacity.sourceforge.net/ for details.

Image Recognition: Facial recognition feature in iPhoto

2009-01-28T10:22:00.007-05:00

I installed Apple's iPhoto '09 last night to test how the face recognition feature (called "Faces", of all things) worked. There are nearly 4,000 photos in my personal library, so I left it running overnight while it went through the database and, I assume, ran its face detection algorithm. I then decided to run a test. I manually identified the same person in two different photographs and had iPhoto go out and locate matches, which is its next step in its learning process - the user next needs to confirm or not confirm the identity of each one of the identifications it produces.

So how did it do at the end of this first step? Surprisingly well is the answer, particularly for a consumer-grade product. The raw numbers were 72 correct and 16 incorrect at this first step, but that doesn't tell the whole story. In the instances where it was incorrect, all but three were confused with family members (which admittedly is the most likely confusion outcome since for all pictures with faces in the database, generally at least one is a family member). In addition, it also correctly chose pictures where only one eye was visible, where the age was significantly different, and where there were different emotions clearly visible on the faces. It also did not seem to have a problem with different compression levels, low resolution (including one that was very granulated), face paint, under-exposure, black-and-white, scans (of printed pictures), and color. Finally, it made only one error out of 86 pictures in correctly detecting and locating the face.

So, even though this was not a properly constructed test, the results were more than impressive enough to warrant looking at it further for professional use in some applications.

PS. This is not a product review, per se, but I should say that my experience with this just-released version was not all positive. Namely, it was horribly slow during the step where one has to select a picture, go into the Faces mode, and then type in the subject's name. Each entry took two to three minutes to accomplish, so I saw the "spinning beach ball" that Mac OS-X uses to let you know it is busy quite a lot. Hopefully this bug will get corrected and patched quickly.

Evidence: Listen to the raw audio evidence

2009-01-27T20:58:00.003-05:00

If you would care to listen to the audio and read the transcripts of the Governor Blagojevich (IL, USA) wiretaps, here is the link.

Image Recognition: Facial and license plate recognition news items

2009-01-27T13:42:00.003-05:00

There are two on-line news articles related to image recognition that I would like to bring to your attention.

The first news article is about law enforcement in Tacoma, Washington, USA using a facial recognition package to match 16 years worth of prisoner mug shots with pictures taken by ATM (Automated Teller Machines) in a forgery and theft investigation to generate the lead needed to solve the case.

The second news article is from New Orleans, Louisiana, USA where local law enforcement used a license-plate recognition system to make 20 arrests and recover 23 stolen vehicles and license plates in a 25 day period.

The common thread here is, of course, automatic image recognition. These software algorithms have come a long way in the last decade. However, one should understand that the conditions are partially or completely controlled in both of these applications - i.e. distance, lighting, exposure, aspect (turned toward the camera), and (possibly) compression all fall within acceptable boundaries. In addition, with the license plate recognition problem, the character set and fonts were known in advance. The controlled conditions and a priori knowledge significantly increase the accuracy of the results tremendously and the chances of a successful investigation and prosecution.

(Hat-tip to JUSTNETNews, USA - I highly recommend this free service of the National Law Enforcement and Corrections Technology Center, or NLECTC, which is part of the National Institute of Justice, USA)

Photoshop: Most blatant Photoshopped covers

2009-01-17T18:04:00.005-05:00

I met a graphics artist today whose job is to "Photoshop" pictures for advertisements. We got to comparing stories and she mentioned an incident involving Kate Winslet, the actress, where her legs were slimmed a bit too drastically and caused a stir. Well, before long we were pulling out my MacBook and Googling for that and other instances of "Photoshopped" covers. Here is the best link we found.

Enjoy!

Legal: Recording conversations in the USA

2009-01-17T15:19:00.008-05:00

Michael Flynn's podcast, Legal Lad's Quick and Dirty Tips for a More Lawful Life, gives an excellent overview of the legalities of making an audio recording of someone in the USA when you are not a government agency performing lawful surveillance. When is it legal and when is it not? The short answer is: it depends - on whether there was a reasonable expectation of privacy, what state the conversation takes place in, and whether all parties being recorded gave consent.

For instance, if one is having a loud conversation on the street (a public place), how can one expect privacy from being overheard? If one can be overheard, how can he then complain that a record (or recording) was made of what he said? An example from daily life, that we can all probably identify with, is the standard phrase we hear when we dial technical support or customer service - "All calls are recorded for quality assurance." In other words - "We're recording you - you've been warned". By being advised and not hanging up, you will likely been seen as having given implied consent.

Legal Lad, being a lawyer as well as having good communication skills, gives a more thorough and educational overview of this subject.

Enjoy!

Careers: Profile of a Court Reporter

2009-01-04T07:02:00.002-05:00

The Wall Street Journal (center-right financial newspaper, USA) has an informative profile of court reporting as a career option. One point from the article that caught my eye was that while training takes only two years and salaries are attractive (at least in the USA), one must learn to type at 225 words a minute with 97% accuracy!

Human Auditory System: Speech Intelligibility overview

2008-12-31T14:24:00.002-05:00

A colleague pointed me to the following overview of speech intelligibility on the Sound & Video Contractor website. It was written for intelligibility during teleconferencing, but the information in it is directly applicable to audio forensics. Special attention should be paid to how reverberation and signal-to-noise ratio (SNR) affect intelligibility.

Enjoy!

Business: Cell phone forensic company sells products for "free"

2008-12-31T09:55:00.004-05:00

This is a departure from the main, science and technology thrust of this blog - I want to talk about the business side of forensics. The motivation is to highlight the government-industry partnership that exists in some countries, such as the grant program discussed in this Philadelphia Business Journal article, to push forensic tools and procedures out into the law enforcement community. The company profiled in the article (BKForensics) got into cell phone forensics through a small US Federal Government grant and then grew from there. This is also a great "lesson" for all of you budding entrepreneurs out there!

(Hat tip to Forensic Focus)

Photography: Year's top ten tips and tutorials

2008-12-31T09:45:00.002-05:00

Digital Photography School has an excellent roundup of ten tips and tutorials for this year.

Enjoy!

Forensic Linguistics: Untangling Tricky Talk

2008-12-24T14:29:00.006-05:00

I have a confession to make - I only got an iPod once a friend convinced me of the merits of university course podcasts. I've since become "addicted" to several technical, news, and business podcasts and would not have it any other way.

One of the podcasts I enjoy on a frequent basis is All in the Mind, by ABC Radio National (Australia). Last week's episode was titled "Untangling Tricky Talk" and covered forensic linguistics as well as transcription by deaf people. The forensic linguistic portion was centered around an interview of Paul Foulkes, who gave a very professional account of his discipline.

Enjoy!

Optics: Adjustable glasses invented

2008-12-23T21:27:00.002-05:00

Inventor Josh Silver (UK) has developed a pair of eyeglasses that are instantly adjustable by inflating or deflating a fluid-filled sac in the middle of the optical surfaces.

Read it all on Gizmodo.

Sonar: US submarines get acoustic signal processing upgrade

2008-12-23T20:55:00.002-05:00

The US submarine fleet is undergoing an overhaul of its sonar signal processing systems. Defense Industry Daily has a short article.

Image Forensics: An interview with Hany Farid

2008-12-23T20:46:00.002-05:00

SiliconValley has an interview with image forensics researcher Hany Farid. My favorite excerpt was this:

Farid first conceived of the possibilities of digital forensics while at MIT, waiting in the checkout line at the library. Restless, he picked up a copy of the Federal Rules of Evidence, then started randomly reading. What he saw startled him: Film and digital images were equivalent evidence, in the eyes of the court.
"This just seemed like a bad idea,'' he said. "Not that I'm good at seeing the future — but I could tell this would be a problem."

Of course, susceptibility to tampering is not the only thing to be considered when evaluating the relative merits of digital imagery as evidence, but it is obvious that tampering with a digital copy is easier to do and (possibly) get away with than tampering with film or tape.

Enjoy!

CCTV: Work continues on automating CCTV surveillance

2008-12-23T19:59:00.002-05:00

Wired News has an article about ongoing research at Ohio State University (USA) in automating surveillance using a network of CCTV cameras. Similar research and product development is occurring at many locations around the world, so I suggest viewing this article as a sample of where things are heading with CCTV technology.

CSI: TV show highlights new fingerprint technology

2008-12-14T20:59:00.003-05:00

WLFI Television (Indiana, USA) did a piece about the television show CSI spotlighting a new fingerprint technology developed by Purdue University. The piece says that it was supposed to air last month. Neither the researchers who developed the technology (led by Professor Graham Cooks) nor the company that now owns it (Prosolia Incorporated) saw the script in advance, so there is no telling whether it was accurately represented.

If any of you readers did see the episode and would like to fill us in, please do!

Imaging: Improvements in through-wall radar imaging

2008-12-02T10:25:00.002-05:00

StrategyPage has a short article about the two latest versions of through-wall radar imagers (namely the Xaver 400 and RadarVision). These devices allow soldiers and police to see objects, including people, on the other side of a wall made of standard building materials, such as concrete, wood, gypsum board (a.k.a. drywall), and the like, but not metal.

These devices work by emitting an RF (radio frequency) radar pulse, listening for the reflection of that pulse off of objects in the wall and on the other side, and using time-delay (i.e. how long it takes for the reflected pulse to come back) and direction (i.e. which direction did the reflection come from) information to construct a picture. This is similar to how bats and dolphins use acoustic echo location, just with an RF pulse instead of sound pulses.

This is a handy capability to have in hostage and other situations where a team has to enter a building where armed attackers or booby traps might be waiting for them. The engineering problems that had to be solved in order to come up with a deployable system were extremely challenging - my had is off to the teams that did this.

Enjoy!

PS. In case you are interested, I posted some time ago about a DARPA (Defense Advanced Research Projects Agency, US Department of Defense) effort that developed a through-wall motion detector which was compact and lightweight - so light-weight that you use it with a single hand, like a stud-finder. That post can be found here.

Biometrics: Request for automation to reduce FBI backlog

2008-11-23T15:40:00.005-05:00

The StrategyPage has a short article on the backlog facing the FBI in analyzing DNA samples - 40,000 samples in the que with a work-off rate of 4 samples per week! Automation will reportedly improve the work-off rate to 200 samples per week.

One data point that would be useful in getting a fuller picture would be the rate that new samples are being added to the que. If anyone has any information on that, please post it in the comments.

The article also gives a brief history of biometrics, starting with appearance (visual) and going through fingerprints (first recognized as unique 4 centuries ago!) and others until the recent methods of gait and DNA.

Enjoy!

Fun: Sew me the music

2008-11-15T03:44:00.003-05:00

Gizmodo highlights a sewing machine by SOUNDS.BUTTER that stitches the time-amplitude waveform of the sound.

Image Forensics: Was North Korean leader's photograph tampered with?

2008-11-09T16:40:00.004-05:00

A photograph was released by the North Korean government last week that purported to show Kim Jong-il, their national leader, reviewing military troops - and looking suspiciously healthy after reportedly suffering a stroke. The Times Online and BBC (both center-left UK newspapers) report on the discrepancies in the photograph, including mismatching shadows and a missing black line.

Fun: All of Murphy's Laws in one place

2008-11-03T21:27:00.001-05:00

Murphy's Laws, the Complete Collection (or so they claim!).

Enjoy!

Physics: A round-up of recent interesting links!

2008-11-01T07:58:00.005-04:00

My aplogies for my light posting of late. Outside commitments have kept me from posting nearly as much as I would like. Here is a collection of links that I have saved up over the last several weeks to blog about. I hope you enjoy them, but please note that some of these are not serious, scientific articles - just because it can be found on the Internet doesn't make it science, much less forensic science! If you are particularly interested in any of the topics addressed below, just let me know and I'll delve further in a future posting.

K-Lite codec package update

X-rays made from Scotch(R) tape (hat tip to A.A.)

Superconductivity Can Induce Magnetism

Deaf people feel their way to speech

Seeing Through The Skin: Optic-less Imaging Technology Could Beat Lens-based Imaging Devices

HOWTO read the secret forensic dots in your laser-printer output

Biometric identifcation by body language

Sound-card oscilloscope

Audio bone headphones

Scientists Watch As Listener's Brain Predicts Speaker's Words

Hidden airport scanner will pinpoint terrorists

Overpaid professions

Military camouflage

Police probe cell phones to catch criminals

How magicians control your mind

How forensic lab techniques work

Computers reassemble pieces of fractured archaeology

Review of Microsoft's Photosynth

Images of atmospheric optics

12 worst Photoshop mistakes ever

Darpa super-resolution vision technology R&D

How other senses adjust to blindness

Family name geographical profiler

Image Recognition: Military requirements push technology forward

2008-10-28T05:38:00.003-04:00

The Strategy Page has an article about how the proliferation of video on the battlefield (e.g. from surveillance cameras and even night vision goggles) is driving technology development. Initially, it was the UK (United Kingdom) that drove image recognition technology with its massive deployment of CCTV in public spaces (e.g. train stations, airports, city centers, and shopping malls). Now, it is the military.

The benefit from computer-assistance in analyzing video comes from the following:

Volume (i.e. the sheer number of cameras and, hence, images to be monitored and/or analyzed)
Concentration (i.e. the human visual system loses the ability to concentrate effectively on images after about 20 minutes of continuous viewing)
Memory (i.e. computers can track and, possibly, predict more things simultaneously than a human can because, generally speaking, computers are not nearly as attention and working-memory limited in the short-term as humans and far outstrip us in their ability to recall video sequences over the long term - they can just play back the video recording off of their hard disks)

The article claims that the abilities of computer systems to recognize patterns is rapidly improving and approaching that of humans - that is no small feat as humans are simply amazing in their ability to perform real-time pattern analysis.

One intriguing point made in the article is that the current conflicts are generating a lot of real-world recordings of "bad behavior" that can be used to train and test new pattern analysis and prediction algorithms - training data like this is like gold to us signal processing types!

Enjoy!

Human Auditory System: Artificial Cochlea

2008-10-09T13:30:00.004-04:00

A next generation implementation of an artificial cochlea has been developed by researchers at the University of Michigan and Tufts University (both in the USA). The natural cochlea is the sea-shell-shaped structure in the human auditory system that is the final stage in the conversion of air pressure variations (a.k.a. sound waves) into neural impulses that convey the frequency and amplitude information information contained in the sound to the brain for interpretation.

EDN (USA technical magazine) has an article which contains more technical detail and pictures on the advance.

I should point out that this version of the artificial cochlea is not an exact replica in form factor (i.e. shape) or function of a natural cochlea. For instance, the artificial cochlea is planar in shape versus sea-shell-shaped; covers the frequency range of 4200 to 35,000 Hz versus the 20 to 20,000 Hz of the human ear; and isn't continually fine tuned by an external processor to focus on frequency bands of interest, like the human cochlea does when one is, for instance, one's brain is picking out a familiar voice in a cocktail party situation. I mention this not to detract from their excellent work, but instead to give you, curious reader, reasonable expectations as to its specifications and performance.

Evidence: Study of the impact of CSI-style shows on jurors

2008-09-26T00:15:00.002-04:00

An overview of the study by researchers at the University of Leicester can be found at Science Daily.

Audio Forensics: New LinkedIn Forensic Audio Group

2008-09-25T13:13:00.005-04:00

Phil Manchester (Force Forensic Audio Specialist, West Midlands Police, UK) has just started a Forensic Audio Group on LinkedIn, the popular professional networking web-service. He plans to use it not only as a way to connect people working or interested in this field, but also as a forum for discussions related to it. I have just joined up myself and I encourage you to do the same if you are keen on audio forensics. The basic membership in LinkedIn is free of charge, as is membership in the group.

Testimony: Memory is fallible, study confirms

2008-09-24T05:07:00.002-04:00

Cosmos (Australian, popular-science magazine) has an article on research by James Ost, University of Portsmouth (UK) into the accuracy of recall, in this case, of video news reports seen some three months prior. There were a couple of interesting statements that popped out at me:

"Ost said that people who were more likely to come up with false memories scored higher on a scale of "fantasy proneness" than those that did not." (My comment - "fantasy proneness" appears to mean "creative" in this context.)

"Ost said that when DNA testing became available in the U.S. in the early 90s, 80 per cent of death row cases that were exonerated, were found to have been wrongly convicted on the strength of mistaken identity."

Although the article doesn't address it directly, previous studies have shown that accuracy of recall also depends greatly on the amount of time that has past since the event, which gives all the more reason to get witness statements soonest.

Image Forensics: Adobe launches CS4

2008-09-24T04:44:00.002-04:00

Adobe has launched the latest version of its Creative Suite, which includes, most importantly for image/video forensic types, Photoshop. Headline features of Photoshop CS4 include:

GPU-based drawing of documents onscreen (for speed improvements)
64-bit for Windows (but not for Mac OS-X, at least yet)
Expanded 3-D paint, lighting and rendering tools

Hat tip: Ars Technica

Linguistics: Forensic Linguistics used on text message evidence

2008-09-16T21:46:00.003-04:00

Dr Tim Grant, Deputy Director of the Centre for Forensic Linguistics at Aston University (UK), is well known in forensic linguistic circles. ScienceDaily has excerpts from an interview with Dr. Grant following the successful conviction of a murderer that relied partly on Dr. Grant's testimony about text messages allegedly sent by the suspect (since convicted) to throw investigators off the trail. I call your attention to the careful and correct use of the phrases "unlikely" and "more likely" to describe the results of the analysis, instead of a phrase such as "proved conclusively".

In addition, here is a link to a BBC (British Broadcasting Corporation, UK) news story about the case and the analysis of the text message evidence. Very interesting stuff!

Acoustics: Listenging to nature

2008-09-14T06:48:00.003-04:00

Using microphones to capture the sounds made by animals in their habitat, minus humans and their man-made sounds. These sounds are known as the "biophony" and are used to sense the quality and character of the animals' habitat. Wired has the story.

Author's comment: It's a good thing that animals don't have privacy rights in the USA (yet!), or these scientists would be in jail for unlawful surveillance activities!

(Via Cross-Spectrum Acoustics)

Fun: Top Ten Amazing Physics Videos

2008-09-08T20:00:00.002-04:00

Wired has them. Enjoy!

Acoustics: Science of sound in the sea

2008-08-27T09:48:00.003-04:00

Sound requires a medium, such as air, to travel in. Here is a link to a site dedicated to the case where the medium is water. The site belongs to the University of Rhode Island (USA) and it has plenty of information for educators and students about the science of sound and the animals that make underwater sounds, such as dolphins, whales, and fish. I particularly liked the recordings of the animal sounds.

PS. Thanks to C.S. for the link!

Human Auditory System: Perfect pitch is more common than previously believed

2008-08-27T09:27:00.002-04:00

It turns out that the ability to identify the pitch of a musical note without needing a reference note to compare to is more common than previously believed. This ability is called "perfect pitch" or "absolute pitch", as opposed to "relative pitch".

Using a testing technique adapted from studies involving infant hearing, researchers at the University of Rochester's Eastman School of Music and Department of Brain and Cognitive Sciences were able to test for perfect pitch in a random sample of people, including people with no musical training whatsoever. In the past, these tests were performed only on people with musical training who could identify notes by name. For more on this study, follow this link.

Fun: Send your voice across a fjord, for the price of a telephone call

2008-08-13T18:52:00.002-04:00

Here is a bit of fun - the Telemegaphone.

(Hat tip: Good Morning Silicon Valley)

Human Auditory System: Tinnitus follow-up

2008-08-09T10:26:00.001-04:00

FYI, I added some new information to my recent post on tinnitus. It can be found here.

Admin: Posting will be light

2008-08-08T09:58:00.002-04:00

Posting will be light for another week or so while I am on summer holidays. Back soon, when I will be "tan, rested, and ready" for more blogging.

Biometrics: Fingerprints versus palm prints

2008-07-24T00:14:00.005-04:00

While driving back from Charleston, SC (USA) today - a lovely seaport city, by the way - I was catching up on my podcasts and happened to listen to a Wall Street Journal (US, center-right, business news) segment on new palm print readers. The part that caught my attention was the claim by one interviewee that - and I'm paraphrasing here - "people" were concerned about using fingerprint biometric identification technologies because they were worried about later being falsely accused of a crime due to a mistaken match to a print left at a crime scene. The interviewee went on to say that as police did not collect palm prints during crime scene investigations, palm print biometrics systems were getting a leg up in the market place.

This made me wonder exactly who are these "people" he referred to? I'm rather doubtful that it is the general public that has these concerns. I find it much easier to believe that elements of criminal "society" or privacy advocates would be tuned-in to these issues, but not the average man on the street. I might be being too critical of this particular piece, but I thought that the reporter should have challenged, or at least followed up on, that statement.

In a larger context, this may unfortunately be a textbook example of how public policy is determined at the chaotic intersection where the general public, subject matter experts, issue advocates, the marketplace, and technology all collide. I certainly hope not!

Admin: National NATIA conference

2008-07-14T19:46:00.004-04:00

I haven't missed many national NATIA conferences over the past twelve years or so, but this year I will unless I can exploit some quantum mechanical effect on a macro scale - I can't be in two places at once. So, I'm off to points south instead of west. Enjoy the conference, you who can attend, and I look forward to hearing about any interesting a/v forensic happenings. Cheers!

Biometrics: Fooling an age verification camera

2008-07-12T17:21:00.002-04:00

Of course, this comes as no big surprise, but it is amusing - a news reporter in Japan used a photograph clipped from a magazine to fool an age verification camera system on a cigarette machine. Link to the Daily Irrelevant post.

Human Auditory System: Experimental tinnitus treatment

2008-07-11T13:06:00.005-04:00

Researchers at the University of Arkansas for Medical Sciences (UAMS) have developed an experimental treatment to help sufferers from tinnitus (also known as "ringing in the ears"). They report that they have successfully treated one patient using a technique known as frequency repetitive Transcranial Magnetic Stimulation (TMS). The treatment scheme involves multiple sessions of this magnetic stimulation with the location of the magnet coil being determined from a PET scan, which is an imaging technique used to see inside of the brain.

The ScienceDaily article says that 17 percent of Americans suffer from tinnitus, but I am not sure what that statistic means - is it "suffer from at some point in their lives", "continually suffer from" or what? It seems from anecodatal evidence to be "continually suffer", but that is besides the point. It will be a step forward if they have developed a safe and effective treatment.

Follow-up: I was speaking to an ENT (Ear, Nose, and Throat) specialist the other day and asked about this statistic of 17% of Americans suffering from tinnitus. He said that that statistic was compiled from medical records - in other words, the number of patients that reported tinnitus symptoms to their doctors. I unfortunately did not think to ask him at the time whether the raw data was then adjusted to account for other factors or not. He also said that taking certain prescription medications, such as Cipro, can result in long-term or permanent tinnitus and that the chances increase if the patient has existing hearing loss (presumably age- or exposure-related).

Human Speech System: Woman acquires new accent after stroke

2008-07-09T06:56:00.002-04:00

ScienceDaily (USA, online research news site) reports on a case in Canada of a woman who developed a new accent after having a stroke. This is a recognized medical condition known as the "foreign accent syndrome". What struck me about this particular case is that

the subject had not been exposed to the newly acquired accent before
the new accent was still in her native language (english)
even after two years of therapy, the new accent persists

I'm not a specialist in brain science, although I do follow it out of curiosity, but it seems to me that this case brings into question exactly how independent or dependent human spoken language accents are on our common brain structures. It seems to beg the question whether the speech-motor area in the brain puts constraints on the formation of accents, and, assuming it does (which seems reasonable), then how much? Is it entirely a matter of coincidence that the damage to her brain resulted in a new, but recognizable, accent? Why not some accent that was unrecognizable? Does the speech-motor area have some type of built-in presets that directly lead to or indirectly influece the development of different accents?

But what does this have to do with forensics, you might ask? Well, for starters consider voice comparison and subject profiling both rely directly and indirectly on understanding how the speech-motor area functions and how accents develop. Fascinating stuff!

Human Auditory System: Beaming sounds into your head

2008-07-09T06:40:00.002-04:00

Journalist David Hambling has written in New Scientist (UK, center-left, popular science magazine) and Wired (USA, center-left, popular technology magazine) about the on-going development of a technology to beam sounds into a person's head using microwaves. This technology is not immediately of practical benefit, judging by the articles, but it is a bit of fun reading.

What I took away from these articles is that there are potential (probable?) health risks when used a high power levels, such as in crowd control applications, so researchers are looking at where it might be useful in low power applications - advertising is mentioned, of course.

As an aside, I noticed the continuation of a pattern that seems to appear with all less-than-lethal "weapons" (i.e. those technologies that seek to incapacitate, drive-off, etc, rather than kill the subjects) - namely, once you label a technology or technique as "less than lethal", this seems to consistently bring with it the hard requirement that it be 100% less-than-lethal in all conditions. Taken to its obvious conclusion, this pattern will make most, if not all, less-than-lethal development projects go bust at some point, for better or worse.

Image Forensics: New blog - Forensic Photoshop

2008-06-30T16:19:00.002-04:00

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: Augmenting video restoration & enhancement with a forensic artist

2008-06-30T16:08:00.003-04:00

The math, science, and technology used in video forensic filtering and forensic video analysis can work minor, and sometimes major, miracles. However, it is not "the be all and end all", as the saying goes. This article in Forensic Magazine uses an actual case to show where a professional forensic artist was able to use knowledge of human physiology and such to generate a full frontal facial drawing of a suspect from a single frame of a security camera video taken at from the standard elevated position. Let's hear it for the liberal art majors!

Computer Audio: Pro Tools now available for Mac OS-X Leopard

2008-06-24T22:37:00.002-04:00

Pro Tools for Leopard is out. I don't use it myself, but I know several audio forensic professionals who do and they swear by it.

Acoustics: Acoustic cloaking

2008-06-24T22:32:00.003-04:00

First there came visual cloaking of tanks, et al. Now, there is a design idea for an acoustic cloak - I should have seen it coming (pun intended)!

Image Recognition: Military uses pattern recognition to detect bomb planting activity

2008-06-24T06:45:00.002-04:00

I wanted to call your attention to an article by the Strategy Page on how the US military in Iraq is using pattern recognition on imagery to detect IED (Improvised Explosive Device) emplacement activities.

A very simple implementation of this technique is to take a picture on Day 1, then another picture from the same location and in the same direction on Day 2. Next subtract the two images from each other and see what is left over. All the things that did not change between the two images will disappear and only those things that changed will be left! In this case, what will be see on the "difference image" might be some disturbed gravel, tire tracks off the side of the road (assuming it is a road-side bomb emplacement) or, if the military guys are really lucky, what will be left is a bunch of guys standing around with shovels and a bomb as they work to put it in place. Neat (and helpful)!

Physics: Physics for Future Presidents

2008-06-23T21:26:00.007-04:00

I freely admit that I am a geek. However, strange though it seems to me, I am not a gadget freak. That being said, even I was won over to podcasting. A friend got me excited about listening to university courses on-line via podcasts (thanks, Amy!). An iPod Nano and iTunes were my ticket to liberation from over-the-air radio during my travels.

With that small confession and short history out of the way, I got the urge today to share one of my favorite podcast courses with you - Physics for Future Presidents, by Richard Muller. His explanation of the issues and science around global warming alone is worth the cost of an MP3 player. You don't have to use iTunes to download it, but it is convenient if you do. Enjoy!

Admin: Teaching

2008-06-23T13:06:00.004-04:00

As mentioned on a previous posting, I am teaching for two weeks - hence the light posting during the last week and, most likely, the rest of this one. I am, however, still moderating comments, so keep them coming!
Best Regards,
Keith

Audio Forensics: Off to a conference

2008-06-03T21:50:00.004-04:00

The Audio Engineering Society is holding its 33rd International conference later this week (June 5-7). The topic is Audio Forensics - Theory and Practice. I'll be there, so if you are able to go, please look me up.

Forensics: New technique recovers fingerprints from bullet casings after firing

2008-06-03T21:40:00.003-04:00

Forensic scientists at the University of Leicester (UK) and Northamptonshire Police (UK) have announced a way to recover fingerprints from fired shell casings. The technique involves the use of an electric charge to attract an electrically conductive powder to the minute amount of corrosion caused by handling the shell casing. The act of firing the bullet actually improves the ability of the technique to recover the print. For more information, see this article from Science Daily.

PS. On re-reading my post, I noticed that I did not supply any answer to the obvious question of "so what?". The reason this technique is particularly interesting is that it potentially provides additional forensic evidence that could identify participants in gun crimes. Imagine being able to re-open a "cold case", for instance a drive-by shooting, using nothing more than a spent shell casing (and a fingerprint database, of course). Hopefully, there will not be any hidden "gotchas" in the details and this technique will be able to fulfill its initial promise.