CEDAR at the AES 26th International Conference: Audio Forensics in the Digital Age

AES 26th International Conference banner

18 July 2005

Held from Thursday 7th - Sunday 9th July 2005 at the University of Colorado and the Adam's Mark Hotel, Denver, the 26th AES International Conference covered many aspects of audio and its connections with modern forensic science.

CEDAR Audio was very active at the conference, with its Managing Director, Gordon Reid, presenting a workshop on The Selection and Use of Adaptive Filters and Associated Signal Processing. This discussed the nature of adaptive filters, and the ways in which they can help to reveal speech in surveillance recordings, even when it is not entirely clear that any is present in the original audio. Mr Reid illustrated his tutorial using genuine examples of air traffic control and surveillance recordings processed on a CEDAR Cambridge Forensic system, and demonstrated how such processing can aid investigators in areas including criminal investigation, terrorism counter-measures, and air accident investigation.

Mr Reid also introduced CEDAR's Retouch™ for Pro Tools, showing how this can be used to suppress or enhance specific sounds during audio forensic analysis. He illustrated the dangers that such powerful signal processing can possess, and how its ability to edit audio without leaving traces or artefacts can be used to alter evidence. He finished the presentation by discussing the consequent need for watermarking technologies to ensure that any such tampering can later be identified.

On the final day, Mr Reid was a panelist in a workshop to discuss the future of audio processing in a forensic context, and described the current work on blind signal separation, the fledgling technology that allows investigators to separate and identify the words of individual speakers, even when they are talking simultaneously on a single, monophonic recording.

Mr Reid and Norman Verrell of HHB Canada (CEDAR's Toronto-based distributor) conducted demonstrations of the CEDAR Forensic System throughout the conference, with equipment supplied by Fraser Jones of CEDAR Audio USA.

The paper, "The Selection and Use of Adaptive Filters and Associated Signal Processing" can be obtained directly from the AES. The presentation used in the workshop is available as a free download from CEDAR Audio's website.

For further information:

CEDAR Audio Limited, 20 Home End, Fulbourn, Cambridge, CB21 5BS, United Kingdom.
t: +44 1223 881771
f: +44 1223 881778
e: info@cedaraudio.com