What Does Crime Sound Like? One student's experience in Forensic Phonetics

Over the summer I worked with a forensic phonetician in London. Forensic phonetics isn’t as it seems on the likes of CSI, yet dealing with real-life criminals on a day to day basis and using phonetics to contribute to the justice system was pretty exciting. Though TV may lead us to believe that a criminal’s voice can be identified within minutes by a computer and that each of us have a unique ‘voice print’ comparable to a finger print, the truth is it takes meticulous phonetic analysis. An analysis based on ‘distinctive features’ is used to conclude whether, to a degree of likelihood, one speaker and another speaker, are in fact the same person. In most cases this would be comparing a recording of a police interview with one from the crime scene, such as CCTV or a 999 call. This analysis is submitted to the court and the forensic phonetician acts as an expert witness who can be subject to gruelling questioning.

At times it is down to a forensic phonetician to work out what is being said, not only who is saying it. This can range from a full transcription of a covert recording to settling a dispute over a single word. To solve such disputes we used many methods, the newest method being measuring the durations of vowels. For example if the dispute is between 2 words, one containing [i:] and one containing [I], instances of these vowels throughout the recording are measured for duration, and it can then be determined which group the disputed vowel falls into.

Forensic work and expert witnessing of any type is fundamental to the justice system and is a way to put your specialist skills (such as linguistics!) to good use. Though forensic phonetics is a growing field it is not very well-known and it is a career which requires an accumulation of reputation and client base.

- Harriet Collier, BA Linguistics Year 3