How we use automatic speaker comparison in forensic practice

Abstract

Automatic methods are rapidly gaining ground in forensic speaker comparison, next to the existing auditory-acoustic methodology, performed by human experts with an academic background in phonetics. In this article we set out the steps that were taken before we could introduce the automatic method and start combining the two methods (software and human) in casework. We further provide a comprehensive explanation of the automatic method (originally written for readers of forensic reports) in the appendix. We discuss the legal reception of the combined approach, based on a court ruling in an appeal case in which the reliability of the speaker comparison was challenged by the defence. We also address the important issue of how conflicting results from the two methods may be dealt with in practice.