Meeting Topic: Earwitness Cases
Moderator Name: Jay Yeary
Speaker Name: Steve Beck
Other business or activities at the meeting: First official Central Texas meeting, describing benefits to future members, elections.
Meeting Location: Austin, TX
The AES Central Texas section is back! The first meeting took place on May 22nd at Mosaic Sound Collective. 52 members and other interested parties came out to join the kick off meeting.
These new officers were voted in by members:
Chair: Rob Murray
Vice chair: Tim Dolbear
Secretary: Aaron brown
Treasurer: Jay Yeary
After electing new officials, we all got to get an insiders look at audio forensic with our guide Steve Beck. Steve has been at the forefront of audio forensics analysis for many years and his talk, Audio Forensics: A Brief Survey and Personal Perspective, showed us all how deep and technical this work can be.
First, he discussed what it means to be an "EarWitness" and physics and psychoacoustics affect earwitness accounts. One interesting fact is that during the day sounds travel upwards and at night sounds travel downwards.
Then Steve showed examples of authenticating audio recordings from the analog age and how it compares to modern spectrographic analysis.
After covering the basics, he discussed how deep analysis of data sets can identify speakers identities with high reliability based purely on other recordings of the speaker. The deep analysis studies, based in part of the work Steve completed in the early 2000's, are responsible for tracking terrorist phone calls and linking terrorists together based on recordings of those conversations.
Another part of audio forensics Steve has been at the forefront of is analyzing gunshots. By recording guns at 7 angles, 4 distances, and with multiple types of recorders, then mathematically compiling the data, Steve and his associates could identify which weapons were fired and how many times they were fired in a recording with accuracy of up to 95%.
These studies are used to help solve cases as well as solve mysteries! Steve used this technology to help National Geographic determine John Hinkley Jr. was the only shooter of President Reagan on March 30, 1981.
A video recording of his enlightening presentation was made and is planned to be added to the AES archives in the near future.
Written By: Aaron Brown