Within-speaker variability in long-term F0 Homa Asadi1, Volker Dellwo2 1Department of Linguistics, Alzahra University, Tehran, Iran 2Institute of Computational Linguistics, University of Zurich, Zurich, Switzerland Center for Forensic Phonetics & Acoustics Introduction Aim of study F0 is considered forensically useful since it conforms to many of the desiderata for FVC parameters (Rose, 2002). F0 is easily extracted and quantified and readily available even in a short stretch of speech. It is also robust to some extent against poor-quality recordings, background noise (in particular non-harmonic noise) and different channel transmissions. Despite its numerous advantages, F0 is sensitive to a large amount of variation within a single speaker. F0 is highly affected by factors such as emotion, state of health, intoxication, voice disguise and recording codecs (Braun, 1995; Gold, 2014). We tried to eliminate factors influencing F0 variation as much as possible. Motivated by the fact that long-term features are less susceptible to within-speaker variability, we aim to analyze long-term features of F0 (namely mean and standard deviation) between recordings of 10 Persian male speakers. Results Participants & speech material LTF extraction Number of speakers= 10 Age= 25 to 28 years old Gender= male Speakers’ language= Persian (Standard Contemporary Persian) 1200 sentences = 10 speakers * 60 sentences * 2 repetitions Average number of syllable per sentence = 12 Measure Factor tested Test Result LTF0-Mean Speaker LM F(141,142)= 39.41, p<0.0001 LTFF0-SD F(141,142)= 0.69, p=0.4 between- and within-speaker variability for the mean of long-term F0 in 10 Persian male speakers Conclusions The results of linear modelling indicated that the effect of speaker is significant for the mean of long-term F0 No main effect was obtained for the standard deviation of LTF0 . The results of within-speaker variability analysis revealed that the variability of long-term distributions of F0 as a function of repetition is not significant. Within-speaker variability was present in speakers 2, 5 ,7 ,8 and 10 which subsequently implies that half of speakers have behaved differently on their two sessions of recording procedures. The results revealed that within-speaker variability was strong across speakers, even though the corpus was extremely controlled in terms of factors influencing variation in F0 measures. References Braun, A. (1995). Fundamental frequency – How speaker-specific is it? In A. Braun and J.P. Köster (eds.) Studies in Forensic Phonetics. Trier: Wissenschaftlicher Verlag, pp. 9-23. Gold, E. and French, J.P. (2011). International practices in forensic speaker comparison. Journal of Speech, Language and the Law, 18, 293-307. Gold, E. (2014). Calculating likelihood ratios for Forensic Speaker Comparisons Using Phonetic and Linguistic Parameters. PhD dissertation, University of York. Rose, P. (2002). Forensic speaker identification. London & New York: Taylor & Francis.