Wednesday, December 31, 2008

Human Auditory System: Speech Intelligibility overview

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.


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

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

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


Wednesday, December 24, 2008

Forensic Linguistics: Untangling Tricky Talk

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.


Tuesday, December 23, 2008

Optics: Adjustable glasses invented

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

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

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.


CCTV: Work continues on automating CCTV surveillance

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.

Sunday, December 14, 2008

CSI: TV show highlights new fingerprint technology

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!

Tuesday, December 02, 2008

Imaging: Improvements in through-wall radar imaging

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.


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.