engleski

Methodological issues in Forensic Phonetics research and real casework

Forensic phonetics research consists of recordings of human participants. Whether phoneticians are interested in conducting specific experiments in order to improve insights on forensic phonetics or to create corpora for further research they need to collect recordings of human participants. Phonetic research is impossible without real, natural spontaneous speech and therefore specific methodology of the field work is required. There are two specific situations we wish to discuss. First is experimental work in forensic phonetics and the second is real casework. When collecting data for experimental work (phonetic differences between specific varieties of language, phonetic differences between different but related languages (e.g. Bosnian, Croatian Serbian), forensic profiling etc.) we have to be careful to collect specific material (stylistically unmarked spontaneous speech for forensic profiling, specific words for suprasegmental research, standardized text for voice quality research etc.) and to record representative speakers. On the other hand, when working on a real casework in forensic phonetics there is a code of conduct (prescribed by the International Association for Forensic Phonetics and Acoustics) which phonetician must follow. One of the issues which might occur during the recordings in real cases is the suspect’s attempt to disguise real voice or manner of speech in general. In those circumstances phonetician must be able to recognize those attempts and use all available means to record speaker in his natural, spontaneous speech. Based on several experiments in different languages it has been proved that speakers when trying to disguise voice usually lower it and they frequently do that while believing that reading a certain text is basis for further speaker comparison work. However, most of the acoustic and auditory analysis is based on a spontaneous speech samples and phonetician has to conduct an interview with the speaker trying to get him to talk about “superficial” topics like his education, origin, free time etc. It is always good to listen to a disputed sample (police recordings) beforehand and try to create a context in which specific words or sentences (from a disputed sample) might occur, especially names, places etc. (to compare accent, vowel pronunciation…) between two samples. To successfully overcome mentioned difficulties it is mandatory for a phonetician to follow recent scientific work in the field and to gain listening experience. Due to experience, experimental research and theoretical background phonetician is able to recognize and overcome difficulties in real forensic phonetic casework.

methodology; forensic phonetics; speaker comparison; acoustic analysis; auditory analysis

nije evidentirano