@article {503,
	title = {Poster: The speaker in speech {\textendash} linguistic context in forensic speaker comparisons},
	year = {2022},
	publisher = {Nederlandse Vereniging voor Fonetische Wetenschappen},
	address = {Utrecht, The Netherlands},
	abstract = {In forensic speaker comparisons, one or more disputed speech samples of an unknown speaker are typically compared to one or more speech samples of a suspect. One concern in such analyses is the effect of phonetic-linguistic context on the speech sounds sampled for comparison; many phonetic studies show that contexts affect the acoustic realization of speech sounds. For example, stressed syllables evoke more canonical pronunciations, utterance-initial speech sounds are typically produced with more effort, and talking over the telephone changes speech behaviour. 

To better understand the relevance of these acoustic effects for forensic speaker comparisons, we have been studying how segmental features that characterize speakers{\textquoteright} voices depend on what speakers are saying (NWO VIDI project 276-75-010). More specifically, how does the speaker-specificity of speech sounds depend on its direct context (Heeren, 2020, Smorenburg \& Heeren, 2020, 2021), on the speech channel (Smorenburg \& Heeren, 2022), and on the language spoken (De Boer \& Heeren, 2020; De Boer, Quen{\'e} \& Heeren, 2022). In this overview presentation we would like to share some of our main project results obtained on existing research databases (CGN, Oostdijk, 2000; D-LUCEA, Orr \& Quen{\'e}, 2017; WYRED, Gold et al., 2018), and show how our findings are relevant for and translate to forensically-realistic speech data taken from the NFI-FRIDA corpus (Van de Vloed et al., 2020).

References

Boer M.M. de, Quen{\'e} H. \& Heeren W.F.L. (2022), Long-term within-speaker consistency of filled pauses in native and non-native speech, JASA Express Letters 2(3): 035201.
Boer M.M. de \& Heeren W.F.L. (2020), Cross-linguistic filled pause realization: the acoustics of uh and um in native Dutch and non-native English, Journal of the Acoustical Society of America 148(6): 3612-3622.
Gold, E., Ross, S., \& Earnshaw, K. (2018). The {\textquotedblleft}West Yorkshire Regional English Database{\textquotedblright}: Investigations into the generalizability of reference populations for forensic speaker comparison casework. In Proceedings of INTERSPEECH (Vol. 2018{\textendash}Sept., pp. 2748{\textendash}2752)
Heeren W.F.L. (2020), The Effect of Word Class on Speaker-dependent Information in the Standard Dutch Vowel /a:/, Journal of the Acoustical Society of America 148(4): 2028-2039.
Oostdijk, N. (2000). {\textquotedblleft}Het corpus Gesproken Nederlands,{\textquotedblright} (The Spoken Dutch Corpus), Nederlandse Taalkunde 5, 280{\textendash}284.
Orr, R., and Quen{\'e}, H. (2017). {\textquotedblleft} D-LUCEA: Curation of the UCU Accent Project data,{\textquotedblright} in CLARIN in the Low Countries, edited by J. Odijk and A. van Hessen ( Ubiquity Press, Berkeley), pp. 177{\textendash}190.
Smorenburg B.J.L. \& Heeren W.F.L. (2020), The distribution of speaker information in Dutch fricatives /s/ and /x/ from telephone dialogues, Journal of the Acoustical Society of America 147(2): 949-960.
Smorenburg B.J.L. \& Heeren W.F.L. (2021), Acoustic and speaker variation in Dutch /n/ and /m/ as a function of phonetic context and syllabic position, Journal of the Acoustical Society of America 150(2).
Smorenburg L. \& Heeren W.F.L. (2022),  The effect of linguistic contexts on the acoustics and strength-of-evidence of /s/. Proceedings 30th annual conference of the International Association for Forensic Phonetics and Acoustics, p. 21-22.
Van der Vloed, D., Bouten, J., Kelly, F., \& Alexander, A. (2018). NFI-FRIDA{\textendash}Forensically realistic interdevice audio database and intial experiments. In 27th Annual Conference of the International Association for Forensic Phonetics and Acoustics (IAFPA) (pp. 25-27).
},
	author = {Willemijn Heeren and Meike de Boer and Laura Smorenburg}
}
@article {489,
	title = {One speaker, two languages: Within-speaker variation of [s] across L1 Dutch and L2 English},
	year = {2021},
	publisher = {Nederlandse Vereniging voor Fonetische Wetenschappen},
	address = {online},
	abstract = {The voiceless alveolar fricative [s] is phonetically similar but not identical in the Dutch and English language. This makes it one of the most difficult English segments to pronounce correctly for native (L1) speakers of Dutch (Flege, 1995). If second language (L2) speakers fail to realize that the Dutch and English [s] have phonetic differences, they may place them into one phonetic category and use their Dutch [s] also when speaking English. Such L1 transfer would be useful for forensic speech science, as it would allow for the inclusion of these segments in cross-linguistic comparisons. 

According to Quen{\'e} et al. (2017), who looked into read speech [s] by L1 Dutch speakers with a relatively high proficiency of L2 English, different [s] realizations are found in L1 Dutch than in L2 English. This implies that [s] is not useful as a feature to perform cross-linguistic speaker comparisons. However, these same speakers have also been recorded producing spontaneous speech, which may be considered more representative for forensic casework data and may evoke less formal language use. Hence, this study investigates the language-dependency of [s] in spontaneous speech.

The language-dependency of [s] was evaluated by comparing the Centre of Gravity (CoG), its standard deviation (SD), and spectral tilt of [s] productions in the same speakers{\textquoteright} L1 Dutch and L2 English (N = 45). Analyses are underway and will be presented at the conference.

References

Flege, J. E. (1995). Second language speech learning: Theory, findings, and problems. Speech perception and linguistic experience: Issues in cross-language research, 92, 233-277.
Quen{\'e}, H., Orr, R., \& van Leeuwen, D. (2017). Phonetic similarity of/s/in native and second language: Individual differences in learning curves. Journal of the Acoustical Society of America, 142(6), EL519-EL524.
},
	author = {Meike de Boer and Willemijn Heeren and Pierce-Melly, Sophie}
}
@article {474,
	title = {Binnensprekervariatie in de uitspraak van /m/ in verschillende talen},
	year = {2020},
	publisher = {Nederlandse Vereniging voor Fonetische Wetenschappen},
	address = {online},
	abstract = {In forensisch zaakonderzoek komt steeds vaker spraakmateriaal in verschillende talen voor. Dit roept de vraag op of er taalonafhankelijke sprekerspecifieke kenmerken zijn. De bilabiale nasaal /m/ is een van de meest sprekerspecifieke segmenten, wat wordt toegeschreven aan de rigiditeit van de neusholte [1]. Tegelijkertijd is de mondholte ook betrokken bij de productie en heeft de tong daarbij geen vaste positie [2]. Hierdoor is er ruimte voor binnensprekervariatie, die mogelijk taalafhankelijk is. Wij onderzochten in hoeverre de realisatie van /m/ verschilt tussen de eerste (L1) en tweede taal (L2) van meertalige sprekers.

Er zijn monologen gebruikt van 53 vrouwelijke sprekers uit D-LUCEA [3], in hun L1 Nederlands en L2 Engels. De sprekers waren eerstejaarsstudenten van University College Utrecht en hadden een bovengemiddelde beheersing van het Engels. De nasalen werden gesegmenteerd in Praat en geanalyseerd op verschillende akoestische kenmerken.

De resultaten laten zien dat de verschillen tussen de realisaties in de L1 en L2 minimaal zijn. Alleen de tweede nasale formant (N2) liet een taalverschil zien: hoger in de L2 dan in de L1. Sprekers verschilden in de mate waarin ze deze verschuiving vertoonden en voor sommigen ging het resultaat in tegengestelde richting.

Hoewel de gevonden L1-L2 verschillen in de uitspraak van de /m/ klein zijn, lijkt de bilabiale nasaal enigszins taalafhankelijk. De N2 wordt gerelateerd aan de mond- en neusholte [4], wat duidt op een aanpassing in de productie. Rekening houdend met deze aanpassing zou de /m/ bruikbaar kunnen zijn in meertalige forensische sprekervergelijkingen. Vervolgstappen zijn om dit te onderzoeken met sprekerclassificatie.

Referenties

[1] Rose, P. (2002). Forensic speaker identification. In: J. Robertson (Ed.), Taylor \& Francis Forensic Science Series. London: Taylor \& Francis (pp. 125-173).
[2] Su, L., Li, K. -P., \& Fu, K. S. (1974). Identification of speakers by use of nasal coarticulation. The Journal of the Acoustical Society of America, 56(6), 1876{\textendash}1883.
[3] Orr, R., \& Quen{\'e}, H. (2017). D-LUCEA: Curation of the UCU Accent Project data. In: J. Odijk \& A. van Hessen (Eds.), CLARIN in the Low Countries. Berkeley: Ubiquity Press (pp. 177-190).
[4] Fant, G. (1970). Acoustic theory of speech production (2nd ed.). The Hague: Mouton.
},
	author = {Meike de Boer and Willemijn Heeren}
}
@article {466,
	title = {Poster: The role of position in native and non-native filled pause acoustics},
	year = {2019},
	publisher = {Nederlandse Vereniging voor Fonetische Wetenschappen},
	address = {Amsterdam, The Netherlands},
	abstract = {In this presentation, we expand our analysis as presented last year on native and non-native filled pauses, now considering the role of position in the utterance. Last year, based on claims by [1, 2] that non-native (L2) speakers would transfer their filled pauses directly from their native language (L1), we compared filled pauses in L1 Dutch and L2 English of female speakers, using linear mixed-effects models. We found that L2 speakers do not simply transfer their filled pauses from their L1 but change their formant realizations and the relative occurrences of um and uh.

Prior studies showed that filled pauses in different positions of the utterance might have different characteristics [e.g. 3, 4]. To test whether the language effects we found could actually be (partly) explained by position effects, we included Position in the fixed parts of our models. We will show that while Position indeed affects filled pause realization, our cross-linguistic findings remain. Overall, results show that when analyzing filled pauses, contextual factors should be considered, including their language, form (uh or um), and position.

References
[1] Clark, H. H., \& Fox Tree, J. E. (2002). Using uh and um in spontaneous speaking. Cognition, 84(1), 73-111.
[2] De Leeuw, E. (2007). Hesitation markers in English, German, and Dutch. Journal of Germanic Linguistics, 19(2), 85-114.
[3] Hughes, V., Wood, S., \& Foulkes, P. (2016). Strength of forensic voice comparison evidence from the acoustics of filled pauses. Journal of Speech, Language and the Law, 23(1), 99-132.
[4] Shriberg, E. E., \& Lickley, R. J. (1993). Intonation of clause-internal filled pauses. Phonetica, 50(3), 172-179.},
	author = {Meike de Boer and Willemijn Heeren}
}
@article {448,
	title = {De realisatie van gevulde pauzes in L1-Nederlands en L2-Engels},
	year = {2018},
	publisher = {Nederlandse Vereniging voor Fonetische Wetenschappen},
	address = {Amsterdam, The Netherlands},
	abstract = {Binnen talen bevatten de pauzemarkeerders {\textquoteleft}uh{\textquoteright} en {\textquoteleft}um{\textquoteright} waardevolle informatie voor forensische sprekervergelijkingen (e.g. Braun \& Rosin, 2015; Hughes et al., 2016). Volgens Clark en Fox Tree (2002) nemen sprekers hun pauzemarkeerders vaak mee van de eerste (L1) naar de tweede taal (L2). Dit voorspelt dat pauzemarkeerders in L1 en L2 forensisch met elkaar vergeleken kunnen worden. Moedertaalsprekers van verschillende talen gebruiken pauzemarkeerders echter verschillend (De Leeuw, 2007; Wieling et al., 2016), wat suggereert dat geoefende L2-sprekers hun gebruik aanpassen.

We onderzochten pauzemarkeerders in spontane spraak van twintig Nederlandse studentes in zowel L1-Nederlands als L2-Engels (minimaal B1-niveau ERK/CEFR; Quen{\'e} et al., 2017). De vraag was hoe deze sprekers {\textquoteleft}uh{\textquoteright} en {\textquoteleft}um{\textquoteright} produceren in beide talen, en hoe vergelijkbaar de realisaties zijn betreffende zowel de proportie uh:um als de fonetische vorm. 

Overeenkomstig Nederlandse versus Engelse moedertaalsprekers (De Leeuw, 2007; Wieling et al., 2016) gebruikten de onderzochte sprekers in het Nederlands twee keer zo vaak {\textquoteleft}uh{\textquoteright} als {\textquoteleft}um{\textquoteright}, terwijl ze in het Engels beide vormen ongeveer even vaak gebruikten. Daarnaast lieten formantmetingen zien dat de centrale klinker in L2-Engels meer open en naar achteren gerealiseerd werd dan in L1-Nederlands. In de presentatie bespreken we tenslotte mogelijke gevolgen voor forensische sprekervergelijkingen.

Referenties
Braun, A., \& Rosin, A. (2015). On the speaker-specificity of hesitation markers. In Proceedings of the 18th International Congress of Phonetic Sciences, Glasgow (pp. 10-14).
Clark, H. H., \& Fox Tree, J. E. (2002). Using uh and um in spontaneous speaking. Cognition, 84(1), 73-111.
Hughes, V., Wood, S., \& Foulkes, P. (2016). Strength of forensic voice comparison evidence from the acoustics of filled pauses. Journal of Speech, Language and the Law, 23(1), 99-132.
De Leeuw, E. (2007). Hesitation markers in English, German, and Dutch. Journal of Germanic Linguistics, 19(2), 85-114.
Wieling, M., Grieve, J., Bouma, G., Fruehwald, J., Coleman, J., \& Liberman, M. (2016). Variation and change in the use of hesitation markers in Germanic languages. Language Dynamics and Change, 6(2), 199-234.
Quen{\'e}, H., Orr, R., \& Leeuwen, D. van (2017). Phonetic similarity of /s/ in native and second language: Individual differences and learning curves. Journal of the Acoustical Society of America, 142(6), 519-524.
},
	author = {Meike de Boer and Willemijn Heeren}
}
