Forensic Phonetics
In addition
to my research/lectures in forensic phonetics, I am the Director of
Forensic Research Associates. FRA specialises in the following areas:
1. Voice Comparison
Comparing voice and speech characteristics of two
or more speech samples with a view to asses the possibility of the speakers
being the same.
2.
Speaker Profiling
Compiling a speaker's linguistic profile
based on his/her speech.
3.
Transcription
Producing a very detailed
description of the content of a recording. This does not only
include speech, but also the presence of other acoustic material
like crying, barking, gun fire, breathing, doors closing, beeps of
an answer machine, etc.
4.
Voice lineups
Assisting the police in carrying
out voice line ups. This includes the careful selection of
phonetically matched foils, pre-testing the voicelineup to ensure
the lineup is fair and instructing the id-parade officers throughout
the preparation phase of the lineup and the lineup itself.
If you need any of the services above, you can contact FRA here:
Limitations of speech-based evidence:
It is important to mention at this point that
speech evidence does not have the same status as evidence based on
DNA or fingerprints. The latter are characteristics of a person
which
can be assumed to be constant. The voice, however, is not, and as a
result no two utterances from the same speaker are ever exactly
identical. The 'voice' is defined by a combination of variables each
of which has degrees of freedom. First, in production: speech is the product of a combination of carefully controlled movements of the vocal organs
of which some - such as the tongue and the lips - exhibit considerable flexibility. The precise articulation of an utterance
will not be
exactly the same on each occasion. The voice can also deviate from
its norm when affected by factors that are outside of the control of
the speaker such as a cold, stress,
fatigue, etc. In other words, a speaker with a cold can temporarily
sound hyponasal. Second, on a 'programming' level, speakers are perfectly
able to adjust their speaking style or choice of vocabulary
depending on the circumstances - for instance, a casual
style of speaking in conversations with friends and family.
They can, however, decide to speak more clearly and choose their
words more carefully when judging the setting to be more formal..
In short: a
speech signal is far from constant. It is therefore important to approach evidence based on speech with
great caution. See
Nolan (2001) for an excellent discussion.
My forensic qualifications
Research
Until September 2008 I was a senior research associate at the
Department of Linguistics at Cambridge University,
investigating the speaker discriminating power of formant dynamics
and sound change patterns in RP speakers.
My earlier research included studying the effects of alcohol
intoxication on speech, voice line-ups, the perception of
speed-manipulated recordings, the effects of repeated copying and
recording on speech intelligibility, and the discriminative power of
the final intonational fall.
Casework
I have
undertaken forensic investigations since 1994, working for both the
defence and prosecution in the USA, UK and the Netherlands.
My forensic work in the
UK
focuses primarily on speaker identification, speaker profiling,
transcription and voice lineups. Earlier forensic work in
the
USA
involved analysis and transcription of surveillance recordings and
flight data recorders (i.e. black boxes) and the acoustic analysis
of gunfire.
Workshops/Conferences
International
Association for Forensic Phonetics and Acoustics Annual Conference
(IAFPA),
Cambridge,
2-5 August 2009.
(Conference Chair)
Forensic Linguistics, 15-16 April 2008, CILR-workshop, University of
Cambridge, UK.
Voices and Identity Workshop: 7
July 2008, DyViS-project, University of Cambridge, UK.
Forensic Phonetics Workshop: 3-5 Oct 2007,
Turkish Headquarters of the Gendarmerie in Ankara.
Tape enhancement , 2003, City University London, UK.
International
Association for Forensic Phonetics and Acoustics Annual Conference
(IAFPA),
July 1995,
Orlando, USA.
Academic background
PhD Linguistics (specialisation Forensic
Phonetics), University of Florida, USA.
MPhil Computer Speech and
Language Processing, University of Cambridge, UK.
BSc (Cum Laude) Computational Linguistics,
University of Groningen, Netherlands.
Professional membership
The International Association of Forensic Phonetics and Acoustics.
The International Society of Phonetic Sciences.
The International
Association of Phonetics.
The British Association of Academic Phoneticians.
Security status:
SC