ABBREVIATIONSPSV Preserved speech variant RTT Rett syndrome AIM Our aim was to contribute new findings related to the pre-regressional verbal development of females with a variant of Rett syndrome (RTT) as the loss of spoken language is one of the key clinical features of RTT, and it would be of particular interest to study the early speech-language development of females who are considered to have preserved some speech-language abilities.METHOD We analysed 461 minutes of audio-video recordings containing play situations and the daily routines of six females (aged 7 to 24 months; mean birthweight 3057g, SD 195g) with the preserved speech variant (PSV) of RTT. All videos were recorded by parents and analysed retrospectively after the diagnosis PSV was made.RESULTS From the age of 7 months onwards, we observed two types of vocalizations, appearing intermittently: (1) apparently normal sequences; and (2) atypical (i.e. inhalatory, pressed, or high-pitched crying-like) vocalizations. Some participants failed to reach the milestone of canonical babbling. We observed a limited phonological and lexical complexity and a restricted compositional variability. Volubility was reduced during the whole period under observation. Hand stereotypies with simultaneous atypical vocalizations appeared only during the second year of life. INTERPRETATIONThe intermittent character of normal versus abnormal verbal behaviours might contribute to an early identification of children with a possible genetic mutation, and provides evidence that speech-language functions are abnormal from the very beginning.Rett syndrome (RTT, MIM 312750), a profoundly disabling neurodevelopmental disorder that predominantly occurs in females, is mainly caused by mutations in the gene MECP2 for the methyl-CpG-binding protein 2 (Xq28).1 It is assumed that MeCP2, a regulator of neuronal activity-dependent synaptic maturation, plays a central role in postnatal brain development. Disruption of MeCP2 affects a wide range of neurodevelopmental functions such as cognitive processes, purposeful hand use, and communicative abilities.2 The pathogenesis of RTT is characterized by a four-stage trajectory, the second of which is the regression period, in which the clinical signs become more prominent.1 The trajectory can be observed in females with classic RTT as well as in other variants of RTT, of which the so-called preserved speech variant (PSV) or Zappella variant (Z-RTT) has a more benign overall pathogenesis, including better manual and speech-language abilities. 1,3,4 Females with PSV have the same staging and a number of the same symptoms as in classic RTT (e.g. the characteristic hand stereotypies) but usually show no general growth failure or deceleration of head growth; epilepsy and hyperventilation are rare.3-5 Furthermore, individuals with PSV show a postregressional improvement in hand use; language abilities may be regained or preserved. Lexicon size and syntactic complexity are reported to increase slowly, but are usually accompanied by features such as e...

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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. KEYWORDS: fluency behaviour, disfluency features, TOFFA, individual differences, speaker-specificity HIGHLIGHTS• A detailed taxonomy of disfluency types (TOFFA) is described.• Individual variation in a range of fluency features is observed.• A consistency study demonstrates the challenges of identifying disfluencies.• The significance of disfluencies for forensic speaker comparison is considered. 3 An examination of the literature yields relatively few studies in which the patterns of fluency phenomena of NF speakers are applied to the speech of PWS. There are however studies where definitions of phenomena found in the literature on stuttering are applied to NF speakers. Johnson, Darley and Spriestersbach (1963) using data first presented in Johnson (1961) provides results of an analysis of the fluency features of 50 male and 50 female PWS and 50 male and 50 female NF speakers. The participants were asked to produce three monologues. Roberts, Meltzer and Wilding (2009) replicated the broad outline of this study using 25 NF adult male speakers. In their summary of the findings of Johnson (1961) and a number of other studies of fluency in NF speakers, Roberts et al. (2009) commented upon the diversity of methods of counting disfluencies in earlier studies. For example, the phenomena may be related to the frequency of occurrence per 100 words or 100 syllables but may not define what is counted as a word or a syllable. Roberts et al. counted interjections including filled pauses and utterances like 'well', 'like', 'you know' into this category. They also counted revisions, repetitions, prolongations and the use of 'excessive force in producing a sound' (2009: 425) which they termed a block. They did not count silent pauses. Roberts et al. relate the fluency phenomena to occurrence per 100 syllables which were defined as target (i.e. idealised phonological) syllables only. They report that individuals produce a range of fluency phenomena per 100 syllables yet even speakers with double the rate of other speakers 'still appear to be speaking well' (2009: 424). Roberts et...

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