Forensic phonetics is the application of the knowledge, theories and methods of general phonetics to practical tasks that arise out of a context of police work or the presentation of evidence in court, as well as the development of new, specifically forensic-phonetic, knowledge, theories and methods. (Quoted from Michael Jessen: Language and Linguistics Compass, 2008)
Within the voice-comparison reports, samples of German and Germanic languages may be analyzed. However, analyses from other language families make up more than half of the case load. For the linguistic analysis of foreign language cases, sworn-in (judicial) interpreters and language specialists are consulted in accordance with the IAFPA Code of Practice, and may contribute to a report.
The majority of recordings are from telephone interceptions, some are derived from other sources of observation methods.
If the material permits for the use of automatic speaker recognition, voice-comparision uses "VOCALISE" for the analysis, and "Bio-Metrics" for a graphic representation of the results. Automatic speaker recognition can not stand alone in a report. A complete report will be comprised of auditory-acoustic analyses as well as automatic speaker recognition, provided, automatic recognition is possible.
In the following paragraph you find a representative selection of current literature on all the aspects of forensic phonetics research and subsequent expert witness reports.
Gfroerer, S., Jessen, M. (2022): Sprechererkennung und Tonträgerauswertung. In: Eckhart Müller/Reinhold Schlothauer/Christoph Knauer (Hrsg.) Münchener Anwaltshandbuch Strafverteidigung (3. überarbeitete Auflage). München, Beck, 2862-2890.
Jessen, M. (2021): "Speaker profiling and forensic voice comparison: The auditory-acoustic approach",
in Coulthard, M., May, A., Sousa-Silva, R. (eds.) The Routledge Handbook of Forensic Linguistics, second edition. Abingdon, UK: Routledge, 382 - 399.
Gerlach, L., McDougall, K., Kelly, F., Alexander, A. (2020): "Exploring the relationship between voice similarity estimates by listeners and by an automatic speaker recognition system incorporating phonetic features", Speech Communication 124: 85 - 95.
van der Vloed, D., Kelly, F., Alexander, A. (2020): "Exploring the effects of device variability on forensic speaker comparison using VOCALISE and NFI-FRIDA. A forensically realistic database", Proc. Odyssey 2020 The Speaker and Language Recognition Workshop, 402 - 407.
Skarnitzl, R., Asiaee, M., Nourbakhsh, M. (2019): "Tuning the performance of automatic speaker recognition in different conditions: effects of language and simulated voice disguise", International Journal of Speech Language and the Law 26: 209 - 229.
Morrison, G.S. and Enzinger, E. (2019): "Introduction to forensic voice comparison", in Katz, W.F. and Assmann, P. F. (eds.) The Routledge Handbook of Phonetics. Abingdon, UK: Routledge, 599 - 634.
Maher, R.C. (2018): Principles of Forensic Audio Analysis. Cham: Springer.
Morrison, G.S., Sahito, F.H., Jardine, G., Djokic, D. Clavet, S., Berghs, S., Goemans Dorny, C. (2016): "INTERPOL survey of the use of speaker identification by law enforcement agencies", Forensic Science International 263: 92 - 100.