Profiling fluency: An analysis of individual variation in disfluencies in adult males

Individual variation in non-fluency behaviour in normally fluent (NF) adults, is investigated. Differences among speakers in the usage of a range of features such as filled and silent pauses, sound prolongations, repetition of phrases, words or part-words, and self-interruptions is explored in the spontaneous speech of 20 male speakers of Standard Southern British English from the DyViS database. The speech analysed is semi-spontaneous, and taken from a simulated police interview task. A taxonomy of fluency features for forensic analysis (TOFFA) was applied to this speech data. The rate of occurrence of each feature per 100 syllables is calculated for each speaker. Results show that individuals vary considerably in the rates of these fluency features occurring in their speech and that between-speaker differences are present in the types of features speakers produce. Implications of the significance of these findings for forensic phonetics are discussed.