Solving The Crime With Audio at AES

The past decade has glorified the crime scene investigation process, as displayed through the popularity of shows including CSI and Law & Order. While these shows are dramatized for television, this doesn't discredit the immense detail that goes into each case. Saturday's tutorial Audio Forensics: An Overview dove into the reality of investigating a crime scene, and how audio plays into the case and in the courtroom.
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Los Angeles, CA (October 15, 2014)—The past decade has glorified the crime scene investigation process, as displayed through the popularity of shows including CSI and Law & Order. While these shows are dramatized for television, this doesn't discredit the immense detail that goes into each case. Saturday's tutoria, "Audio Forensics: An Overview," dove into the reality of investigating a crime scene, and how audio plays into the case and in the courtroom.

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With any case, audio plays a vital role in the examination process, as outlined in each of the four presentations during the session. Eddy Brixen, a Denmark-based ebb-consultant, gave three examples of how audio played into the solving of a variety of crimes, from shootings, to protests, to domestic violence.

One example was a 2007 protest in Copenhagen, where arrested demonstrators argued that they could not hear the police messages warning them to vacate the area over the sounds of gunshots, firecrackers and helicopters at the site. This led forensic analysts to examine the site of the demonstration and factor in all the barriers that could prevent the protestors from hearing the police messages.

"The forensics looks at the space to determine if it was possible that they couldn't hear the message," said Brixen. He said professionals looked closely at the space, distracting background sounds, and barriers that could distort or block the messages.

Audio also plays a big factor in the courtroom, as professionals need to consider room acoustics, noise reduction, barriers, surveillance, processing, and more to make sure a single recording is heard as clearly as possible.

"It's vital that audio is of sufficient quality to be monitored for long periods of time," said presenter Gordon Reid of CEDAR Audio Ltd.

Through numerous studies, Reid was able to demonstrate how audio factors into the courtroom, and how when playing an audio recording background noise can reduce the speech intelligibility, but still plays a role in the evidence of the case.

"Processing must be in real-time and latency must be unimportant," he said.

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