Audio forensic experts have more voice identification cases today than ever before. Legal cases have more audio evidence than ever before, and voice identification has become a critical component to many legal proceedings. Voice mail, confidential informant recordings, call verification centers, 911 and other digital audio recordings often time require confirmation of the identity of person speaking.
There are times when the accused is not the person speaking in the recording and it is the audio forensic expert’s job to scientifically prove this conclusion.
The first step in conducting voice identification is for the audio forensic expert to understand how the audio evidence recording was created. The next step is to create an exemplar using as close to the exact same recording methods as possible that were used to create the original to create the exemplar.
An audio exemplar is a recreated audio recording of the person’s voice that is thought to be speaking on the evidence recording. The exemplar is created using as exact recording tools as the original was created with. If the evidence recording was a telephone intercept, the audio forensic expert would use a telephone intercept to record the exemplar. Of course, other considerations will come into play as the audio forensic expert determines necessary to maintain the integrity of the voice identification process.
Scientific standards written by the Audio Engineering Society as well as the American College of Forensic Examiners International are referred to by the audio forensic expert when conducting the voice identification. Those standards can be found on the websites of both organizations.