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Personal Information Gea de Jong-Lendle
Official Name & Address
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Dr. MPhil. Gea de Jong-Lendle Philipps-Universität Marburg |
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Academic posts
| 2017- | Senior Lecturer/Scientist (Studien Rätin), Philipps-Universität Marburg |
| 2016- | Head Forensic Phonetics, Philipps-Universität Marburg – Curriculum/Research/Casework Specialisation: speaker comparison, speaker profiling, transcription, and voice lineups. |
| 2016-2017 | Deputy-Professor (Vertretungsprofessur), Philipps-Universität Marburg |
| 2010-2016 | Senior Scientist/Lecturer (Akademische Rätin): Phonetics Department, Institut für Germanistische Sprachwissenschaft, Philipps-Universität Marburg |
| 2006-2008 | Senior Research Associate, Department of Linguistics, University of Cambridge |
| 2000-2005 | Researcher/Lecturer, Language and Communication Science Dept. City University, London. |
| 2000-2005 | Lecturer, M.Phil. Computer Speech and Language Processing, Engineering Dept, Cambridge University. |
Academic Qualifications
- 1998 PhD. Linguistics, Linguistics Department, University of Florida, Gainesville, USA.
Thesis: Earwitness Characteristics and Speaker Identification Accuracy - 1993 MPhil. Computer Speech and Language Processing, Engineering Department,
University of Cambridge, UK. - 1992 BSc. Computational Linguistics, Cum Laude (Artificial Intelligence),
University of Groningen, NL. - 1988 Propaedeutics Dutch Language, Dutch Department, University of Groningen, NL.
Academic responsibilities – current/recent
- since 2016 Head Forensic Phonetics, Curriculum/Research/Casework, Philipps-Universität Marburg
- 2024 Organiser – VoiceID Marburg
- 2023 Scientific Chair - Section: forensic phonetics, ICPhS
- 2021 Chair of the IAFPA-Conference Marburg (online)
- since 2022 Chair Graduation Ceremony Organisation
- since 2021 Tonight Show – Interview with forensic phoneticians
- since 2010 Equal opportunity and Women’s representative
Short CV
Since 2016 I am responsible for Forensic Phonetics in Marburg regarding curriculum, research and casework.
Since 2010 I am a senior scientist/lecturer in phonetics at the University of Marburg in Germany. My main research interests focus on the area of forensic and perceptive phonetics. Other academic posts include Senior Research Associate at the University of Cambridge, Lecturer at City University in London and Guest-Lecturer at the University of Cambridge.
In addition to my work as a lecturer/researcher at the University of Marburg, I actively participate in training programs for police/justice departments and educational institutions (Selm-Bork: Hessen LKA Fortbildungsgruppe, Münster: Deutsche Hochschule der Polizei, Wiesbaden: HLKA Beratergruppe).
Since 2007, I provide consultancy for developing forensic laboratories as a forensic expert for the European Commission.
I have undertaken forensic investigations since 1994, for both prosecution and defense. Currently, I am leading a forensic phonetics team in Marburg conducting forensic analyses in civil and in criminal cases for different police forces in Germany. In the past, I have provided voice analysis services for a number of UK institutes/forces like the Forensic Science Service, Metropolitan Police and Liverpool Police and assisted the Dutch police.
I hold a PhD in linguistics from the University of Florida, an M.Phil. in Computer Speech and Language Processing from the University of Cambridge and a BSc. in Computational Linguistics from the University of Groningen.
Native speaker of Frisian (West-Frisian: Wâldfrysk variety) and Dutch. Fluent in English and German.
Publications and talks
List of selected publications Hollien, H., Liljegren, K, Martin, C.A., DeJong, G., 1999 Prediction of intoxication levels by speech analysis, Zeitschrift für Dialectologie und Linguistik, Stuttgart, Steiner. 106:40-50. Hollien, H., DeJong, G., and Martin, C.A., Schwartz, R. and Liljegren, K., 2001 Effects of ethanol intoxication on speech suprasegmentals, J. Acoust.Soc.Amer.110(6), 3198-3206. DeJong, G. and Honess, T. 2002 The Perception of Speed-Modified Recordings. J. Forensic Linguistics, 44-57. DeJong, G., Newis, P.R. and Hunt, J. 2002 The effects of repeated copying and recording media on intelligibility, J. Forensic Linguistics, 58-73. F. Nolan, K. McDougall, G. de Jong and Hudson, T. 2006 A Forensic Phonetic Study of 'Dynamic' Sources of Variability in Speech: The DyViS Project. In: P. Warren and C.I. Watson (eds.), Proceedings of the 11th Australasian International Conference on Speech Science and Technology, 6-8 December 2006, Auckland: Australasian Speech Science and Technology Association, 13-18. DeJong, G., McDougall, K. and Nolan, F. 2007 Sound change and speaker identity: an acoustic study.
In: Christian Müller and Susanne Schötz (eds.), Speaker Classification. Springer.Hudson, T., DeJong, G., McDougall, K., Harrison, P., and Nolan, F. 2007, F0 statistics for 100 young male speakers of standard southern British English, Proceedings of the 16th ICPhS, August, Saarbrucken, Germany. Nolan, N., McDougall, K., de Jong, G. and Hudson, T. 2009 The DyViS Database: Style-Controlled Recordings of 100 Homogeneous Speakers for Forensic Phonetic Research. International Journal of Speech, Language and the Law 16.2. Duckworth, M. McDougall, K., de Jong, G. and Shockey, L. 2011 Improving the Reliability of Formant Measurement. International Journal of Speech, Language and the Law, vol 18.1 2011 35–51. DeJong-Lendle, G., Nolan, F., McDougall, K., and Hudson, T., 2015, Voice lineups: a practical guide. Proceedings of the 17th ICPhS, August, Glasgow, UK. DeJong-Lendle, G. 2016 Book Review: M. Jessen, Phonetische und linguistische Prinzipien des forensischen Stimmenvergleichs, Zeitschrift für Dialektologie und Linguistik. DeJong-Lendle, G. 2016 Der Strafprozess des Jahrhunderts - Die Geschichte eines Piloten, eines deutschen Immigranten, einer skeptischen Wissenschaftlerin und des Beginns der forensischen Phonetik, Literaturkritik.de, August 2016, Marburg: LiteraturWissenschaft.de. Urke, F., Reetz, H., and De Jong-Lendle, G. 2016 Die Wahrnehmung reduzierter Sprache unter Rauschen, Conference Proceeding Phonetik & Phonologie (P&P), München. de Jong-Lendle G. (2022) Speaker Identification. In: Guillén-Nieto V., Stein D. (eds) Language as Evidence. Palgrave Macmillan, Cham. https://doi.org/10.1007/978-3-030-84330-4_9. Selection of recent talks Rinke, P, Beier, K., Kaul, R. Schmidt, T., Scharinger, M. and DeJong-Lendle, G., 2021 ` Neurophysiological evidences for automatic speaker recognition: Neural correlates of voice familiarity´, Talk presented at the International Association for Forensic Phonetics and Acoustics Annual Conference, Marburg, 22-25 August. Martin, S., DeJong-Lendle, G., Kehrein, R. and Duckworth, M. 2021 ‚The variability of stuttering: A forensic phonetic study’, Poster presented at the International Association for Forensic Phonetics and Acoustics Annual Conference, Marburg, 22-25 August. DeJong-Lendle, G., Wack, H., Kehrein, R., Kaul, R., Rinke, P., Beier, K., Schmidt, L. 2021 ` Auditory motorcycle recognition: Experts vs Non-Experts´, Poster presented at the International Association for Forensic Phonetics and Acoustics Annual Conference, Marburg, 22-25 August. DeJong-Lendle, G., 2021 "Die Stimme der Täter: Was forensische Phonetiker_innen machen. Möglichkeiten und Grenzen”, Heinrich-Heine-Universität Düsseldorf, Oktober 1. DeJong-Lendle, G., 2021 ‘The voice of crime. An introduction to forensic phonetics. The Chinese University of Hongkong, November 26. DeJong-Lendle, G., 2022 ‘Forensic phonetics: past and present. Conference: Forensic Linguistics. The University of Verona & The free university of Bozen/Bolzano, May 20. Moeller, S. and De Jong-Lendle, G. 2022 ‘When singing becomes illegal’, Poster presented at the International Association for Forensic Phonetics and Acoustics Annual Conference, Prague, 10-13 July 2022. Siewert, M., Gerlach, L., Alexander, A., DeJong-Lendle, G., Lameli, A. and Kehrein, R., 2023 ‘Automatic Speaker Recognition – Does Dialect Switching matter?’, Poster presented at the International Association for Forensic Phonetics and Acoustics Annual Conference, Zürich, 9-12 July 2023. Lieb, A. and DeJong-Lendle, G. 2023 ‘The Vocal Parameters of Dissociative Identity Disorder’, Poster presented at the International Association for Forensic Phonetics and Acoustics Annual Conference, Zürich, 9-12 July 2023. DeJong-Lendle, G. 2023 Voice lineups: a comparative study of current methods, International Language and Law Association (ILLA) 19-22 September, Krakow, Polen. DeJong-Lendle, G., 2023 "The voice of crime, an introduction to forensic phonetics”, the Language, Intersensory Perception, and Speech (LIPS) Lab, Psychological and Brain Sciences University of Massachusetts Amherst, October 11. DeJong-Lendle, G. and Kehrein, R. 2024 "Wer bin ich? Was Sprache und Aussprache über Menschen verraten”, Ringvorlesung „Dem Verbrechen auf der Spur“. Rechtsmedizin und Kriminaltechnik, Institut für Strafrecht und Strafprozessrecht, Universität zu Köln, 30 Januar. DeJong-Lendle, G., 2024 ‘Tatort Marburg: forensische Phonetik, Philipps-Universität Marburg, Forum 09. 31 Januar. DeJong-Lendle, G. 2024 "Alles was Sie sagen...kann gegen Sie verwendet werden. Die Rolle der forensischen Phonetik in Kriminalverfahren”, das Norddeutsche Linguistische Kolloquium zum Thema „Von der Theorie zur Praxis: Linguistik und ihre Relevanz für die Gesellschaft“, Leibniz Universität Hannover, 21 März Teaching
Foto: Gea de Jong-Lendle Teaching - current
Perzeptive Phonetik
Akustische Phonetik
Einführung in die PhonetikDie forensisch-phonetische Analyse deutscher Dialekte (with R. Kehrein)
Forensische Phonetik
Sprechererkennung
Practical forensic phonetics workshopTechniken für Sprachanalyse
Sprachtechnologie für die Sprechwissenschaft
Grundlagen und Anwendungen der Schallspektrographie
Messung und Interpretation von akustischen Sprachdaten (with A. Werth)
Audio Technik (with H. Wack)Artikulations- Transkriptions- und Hörübungen I – Basics of phonetic transcription
Artikulations- Transkriptions- und Hörübungen II – Phonetic transcription of dialects
Artikulations- Transkriptions- und Hörübungen III – Phonetic transcription of pathological speechKontrastive Phonetik: Deutsch – Niederländisch
Kontrastive Phonetik: Deutsch – Englisch
Ausspracheunterricht – die Laute des Deutschen
Teaching – International
Courses:
City University London, UK
Cambridge University, UK
University of Florida, USAWorkshops:
European Commission – Projekt EuropAid:
Police Department Ankara, Turkey (2007)
Kosovo (2020)ERASMUS:
University of Alicante, Spain (2017)Public outreach
Public outreach: Press interviews
2020 Was macht ein forensischer Phonetiker? , Technology Review 6/2020, Karriere,
DeJong-Lendle, G., interviewed by Joseph Scheppach.2021 Was verrät die Stimme einer Person über ihr Alter? – National Geographic-
Wissenschaft. 8 Juni 2021, interviewed by Barbara Buenaventura2022 Wenn ein kleiner Seufzer den Entführer verrät – Süddeutsche Zeitung Nr. 22, Freitag
28 Januar 2022, Lernen. Juni, interviewed by Martina Kind2022 Die Stimme entlarvt den Verbrecher – Neue Zürcher Zeitung (NZZ), Saturday
November 12, Forschung und Technik, interviewed by Piotr Heller.2023 Die Stimme: Warum sie ein Verräter ist – GEO, interviewed by Maria Kyradi.
Public outreach: Tonight show – Interview with forensic experts
2021 Guests: Prof. Francis Nolan and Dr. Tina Cambier-Langeveld
Guest: Prof. Peter French (Christmas Special)
2022 Guest: Jos Vermeulen (Christmas Special)
2023 Guest: Prof. Angelika Braun (Christmas Special)
Forensic Phonetics
What is the meaning of forensic phonetics?
„Forensic“ describes the use of scientific knowledge and methodology in the investigation and establishment of facts in a legal context.
„Phonetics“ is the scientific study of speech sounds. Phoneticians study the production and transmission of sounds and how these are perceived (Crystal, 2010; Kohler, 1977, p. 25).
Whereas forensic text analysts study written documents, the primary object of investigation for a forensic phonetician is the audio signal or the voice. In that sense, forensic phonetics can be understood as one of the applied phonetic sciences that deals with sound aspects that are relevant to the justice system.
What does a forensic phonetician do?
In the early sixties, the work of forensic phoneticians was primarily devoted to speaker identification (French, 1994). Since then, we have seen a diversification of tasks. At present, forensic phonetic areas comprise speaker identification/comparison, audio transcription and audio enhancement. Other less common tasks are speaker profiling, audio authentication and voice line-ups. A description of each task is provided in the table below. The exact distribution of task types may vary somewhat depending on whether a particular forensic team or expert has special expertise or a specific tool. An example of such a tool would be the dialect information system at the Research Centre of the “Deutscher Sprach Atlas” at the University of Marburg described below (Schmidt, J. E., Herrgen, J., Kehrein, R., & Lameli, A., 2008).
Tasks in forensic phonetics
| Speaker comparison | The analysis, by ear and specialised sound- and audio software, of two recorded speech samples. The disputed sample is the speech of an unknown perpetrator, e.g. the voice in the background of an emergency call or the bank robber shouting on a security camera. The reference sample is the speech of a suspect, e.g. in a police interview, on a surveillance recording or in a recorded phone call. The aim of the phonetic analysis is to evaluate the degree of consistency between the samples and, where consistent, the degree of distinctiveness of the different features analysed. |
| Speaker profile | A speaker profile is requested for intelligence purposes and consists, if possible, of a description of speaker features to limit the number of possible suspects. These features may include the sex of the person, an estimation of his/her age, dialect, foreign accent, idiosyncrasies or even level of education or profession based on the sociolect or jargon used by the speaker. |
| Audio-transcription | Producing a detailed description of the content of a recording. This does not only include speech, but also non-verbal material like crying, barking, doors closing, beeps of an answer machine, car engine noise, gun fire, etc. The transcript can serve two purposes: 1) to assist in forensic investigations: surveillance recordings may exist from a car that was used to transport drugs or a “Black Box” recording is recovered from a crashed plane, 2) to be used as incriminating evidence in court (e.g. The defendant may mention the transfer of money on tape AS2). |
| Audio-enhancement | The quality of a recording can be degraded by noise and distortion resulting from inadequate equipment and recording methods or the acoustic environment in which it was produced. The intelligibility of a recording can be enhanced through the application of digital frequency filters and through the use of high quality equipment. In a first stage, specialised software is employed to analyse the spectral characteristics of the signal. Based on this analysis filters are constructed to e.g. reduce the intensity of particular frequencies (in the case of disturbing noise like mains hum, wind or ventilators) or increase in the case of speech, both to improve the intelligibility of the recording. |
| Audio-authentication | Examining whether the recording is authentic or whether it has been modified. Authentication analysis may also include assessing how the recording was made and which equipment was used. |
| Voice lineups | Assisting the police in the construction of a voice identification parade. This procedure is applied in cases, where a witness has heard the voice, but not seen the face of the speaker and a recording of the crime does not exist. |
Are voices unique? Do “voice prints” exist?
The term “voice print” is considered problematic by forensic speech experts using the non-automatic auditory/acoustic analysis method. It suggests that there is a unique and stable voice print that can distinguish individuals as much as fingerprints can. Unlike fingerprints however, variability occurs at a number of different levels in the speech process (Nolan 1991). Some of it can be controlled, like speaking style (e.g. the use of formal versus informal language or the speed of articulation), some of it is imposed like changes concerning a speaker’s physical state (e.g. a cold may give a speaker’s voice quality a hyponasal quality).
As a consequence formulating the outcome of a speakercomparison analysis as: “Speaker A heard on audio recording X is indeed Mr. Blofeld” would theoretically be incorrect. Instead forensic experts in their reports will (normally) formulate their findings in terms of probabilities, as recommended in the casework guidelines of the European Network of Forensic Science Institutes (ENFSI 2015).
We are members of The International Association for Forensic Phonetics and Acoustics (IAFPA). This is the professional association for forensic scientists and researchers who analyse voices, speech and audio recordings. As members we follow the IAFPA standards of professional conduct and procedure described in their Code of Practice.
You can also find this information in German.
Dialectology in Marburg – Georg Wenker
A dialect may take the form of a small number of dialectal features in the otherwise fairly standard variety to a large number of deviations from the standard language in a rather traditional dialect. In the case of a speaker profile, a detailed feature analysis may give the phonetician an idea of the region, where the speaker spent their youth, or where the foreign speaker may have learnt their German.
The Deutsche-Sprach-Atlas in Marburg is particularly fortunate to have inherited the old dialect maps of Georg Wenker (1852–1911), a linguist who collected dialectal information from approximately 40,000 different places in Germany. The Wenker database was incorporated into a dialectological Information System called REDE (www.regionalsprache.de) together with another 30 linguistic databases on German dialects and a number of related/neighbouring languages like Dutch and Frisian.
Using the REDE system in the case of a speaker exhibiting dialectal features, it is possible to identify a region based on the area that all feature filter maps share.
Studying forensic phonetics
You want to train as a forensic phonetician in Marburg?
When you are looking to obtain an MA degree:
MA Sprechwissenschaft und Phonetik:
Follow the forensic route within the MA Sprechwissenschaft und Phonetik. This degree not only offers modules focused on forensic phonetics, also other courses like acoustic phonetics and IPA-transcription are taught from a forensic perspective.Important: although all forensic courses are taught in English, other courses that are part of the standard curriculum are in German.
When you are looking for a short-term visit:
National and international students can also visit for a semester either as part of an exchange program (e.g. ERASMUS, ERASMUS+), a free mover or a guest student (GasthörerIn). Information can be found here.
Courses:
The following courses, all taught in English, may be useful for visitors with a forensic interest:
MA-Sprechwissenschaft und Phonetik:
Forensic phonetics (Vorlesung: Forensische Phonetik 1)
Speaker recognition (Seminar: Forensische Phonetik 2)
ATH2 - narrow IPA-transcription of dialects/foreign languages (Übung Transkription 1)BA-Sprache und Kommunikation:
ATH1 – Basics of IPA transcription (Übung: Wissenschaftliche Methoden in der Linguistik: ATH I)These are only offered in the Summer (mid-April until mid-July). Exact term dates can be found here.
Contact person:
To ensure a place on the course/degree or if you have questions, please write an email to Gea de Jong-Lendle: dejong@staff.uni-marburg.de. It is recommended you do this well before your visit to Marburg, so that we are able to make the proper arrangements.
Speech analysis services (Sprach Analyse)
For speech analysis or general consultancy, please contact Gea de Jong-Lendle: dejong@staff.uni-marburg.de.
Literature
Introductory de Jong-Lendle G. (2022) Speaker Identification. In: Guillén-Nieto V., Stein D. (eds) Language as Evidence. Palgrave Macmillan, Cham. https://doi.org/10.1007/978-3-030-84330-4_9 Gfroerer, S., and M. Jessen (2022). ‘Sprechererkennung und Tonträgerauswertung’, in Eckhart Müller and Reinhold Schlothauer and Christoph Knauer (eds), Münchener Anwaltshandbuch Strafverteidigung (3. überarbeitete Auflage). München: Beck, 2862-2890. Hollien, H. (1990) The Acoustics of Crime. Plenum Press: New York. Jessen, Michael (2012) Phonetische und linguistische Prinzipien des forensischen Stimmenvergleichs, Lincom: München. Künzel, HJK. (1987) Sprechererkennung. Grundzüge forensischer Sprachverarbeitung. Heidelberg. Advanced Hollien, H. (2002) Forensic Voice Identification. Academic Press: San Diego. Rose, P. (2002). Forensic Speaker Identification. Taylor & Francis: London. Nolan, F.J. (1997) Speaker recognition and forensic phonetics. In W.J. Hardcastle & J.Laver (eds.) The Handbook of Phonetic Sciences. Oxford: Blackwell. pp. 744-767