AES 46th Conference on Audio Forensics

Pre-Conference Workshop


       Home  /  Conference Details  /  Program  /  Keynote  /  Registration

Venue & Accommodations  /  Social Event  /  Pre-Conference Workshop

Classes in Forensic Audio  


The National Center for Media Forensics is hosting a special Pre-Conference workshop the evening before the official conference proceedings.  This workshop is only open to conference registrants and is included with conference registration.  Space is limited, please contact the NCMF to reserve your seat.  The articles below will be emailed to you upon registration.  

Date: June 13th 5:30-8:30 PM

Location: The National Center for Media Forensics, 1800 Grant Street, Denver, CO (across the street from the site of the conference, The Warwick Hotel)

Register: contact Leah Haloin at [email protected] with the following information - Full Name, Company/Organization Affiliation, E-Mail Address, Phone Number




Workshop on Validity and Reliability in Forensic Voice Comparison 

Presenter: Geoffrey Stewart Morrison 

Director, Forensic Voice Comparison Laboratory, School of Electrical Engineering & Telecommunications, University of New South Wales


This workshop looks at validity and reliability in forensic voice comparison in light of recent events affecting forensic science in general. The workshop begins with a summary of the response to the 2010 R v T ruling by the Court of Appeal of England & Wales. Numerous leading forensic scientists from around the world have reiterated that the likelihood-ratio framework is the logically correct framework for the evaluation of forensic evidence. I also take this position, but in a very muddled way the R v T ruling raises another concern, which was also a major concern of the 2009 US National Research Council report: validity and reliability. How should validity and reliability be measured within the likelihood-ratio framework and in particular for forensic voice comparison? This workshop addresses this question both at a philosophical level and a technical level. Sub-questions addressed include: How should appropriate test databases (and also appropriate background and development databases) be selected? What should be the characteristics of an appropriate metric of validity? What should be the characteristics of an appropriate metric of reliability? The latter part of the workshop will include detailed  description of particular metrics, the log-likelihood-ratio cost (Cllr) and credible intervals.


Copies of the following articles will be provided to registrants who are requested to read them prior to the workshop:

– Morrison, G. S. (2012). The likelihood-ratio framework and forensic evidence in court: A response to R v T. International Journal of Evidence and Proof, 16, 1–29. doi:10.1350/ijep.2012.16.1.390

– Morrison, G. S., Ochoa, F., & Thiruvaran, T. (2012 in press). Database selection for forensic voice comparison. In Proceedings of Odyssey 2012: The Language and Speaker Recognition Workshop, Singapore. International Speech Communication Association.

– Morrison, G. S. (2011). Measuring the validity and reliability of forensic likelihood-ratio systems. Science & Justice, 51, 91–98. doi:10.1016/j.scijus.2011.03.002



Dr Geoffrey Stewart Morrison received his PhD from the University of Alberta in 2006. His dissertation focused on statistical modeling of speech data. He began working on forensic voice comparison in 2007  as a Research Associate with Dr Philip Rose at the Australian National University. Since 2010 he has been a Senior Researcher and the Director of the Forensic Voice Comparison Laboratory, School of Electrical Engineering & Telecommunications, University of New South Wales. He is also an Invited Lecturer in the Judicial Phonetics Specialization, Master in Phonetics and Phonology Program, Spanish National Research Council / Menéndez Pelayo International University, an Adjunct Associate Professor in the Department of Linguistics, University of Alberta, and is Chair of the Forensic Acoustics Subcommittee of the Acoustical Society of America. In collaboration with the Australian Federal Police, New South Wales Police, Queensland Police, National Institute of Forensic Sciences, Australasian Speech Science and Technology Association, and the Guardia Civil, he is the lead researcher on an Australian Research Council Linkage Project on making demonstrably valid and reliable forensic voice comparison a practical everyday reality in Australia. He has published on forensic voice comparison and on the evaluation of forensic evidence in leading journals in acoustics, speech processing, forensic science, and law. (Any opinions expressed by Dr Morrison are his own and do not necessarily represent the policies or opinions of any of the above-mentioned organizations or individuals.)


AES - Audio Engineering Society