Spatial and temporal lingual coarticulation and motor control in preadolescents.

PURPOSE In this study, the authors compared coarticulation and lingual kinematics in preadolescents and adults in order to establish whether preadolescents had a greater degree of random variability in tongue posture and whether their patterns of lingual coarticulation differed from those of adults. METHOD High-speed ultrasound tongue contour data synchronized with the acoustic signal were recorded from 15 children (ages 10-12 years) and 15 adults. Tongue shape contours were analyzed at 9 normalized time points during the fricative phase of schwa-fricative-/a/ and schwa-fricative-/i/ sequences with the consonants /s/ and /ʃ/.

Coarticulation as an indicator of speech motor control development in children: an ultrasound study.

There are still crucial gaps in our knowledge about developmental paths taken by children to adult-like speech motor control. Mature control of articulators during speaking is manifested in the appropriate extent of coarticulation (the articulatory overlap of speech sounds). This study compared lingual coarticulatory properties of child and adult speech, using ultrasound tongue imaging.

The 'trough effect': an ultrasound study.

Bilabial stops often show a lowering of the tongue in symmetrical VCV sequences. The causes of this phenomenon, sometimes called the 'trough effect', are unknown. However, it could have important implications for the study of time-varying aspects of speech events.

Dysarthria and Friedreich's ataxia: what can intelligibility assessment tell us?

Background: Friedreich's ataxia is one of the most common hereditary disorders of the nervous system. Dysarthria is a pervasive symptom of Friedreich's ataxia, yet the clinical presentation of speech symptoms remains poorly understood, leaving clinicians without the evidence required to develop therapy interventions.

Aims: The research reported herein had three aims: the first was to document the severity of the intelligibility deficit associated with Friedreich's ataxia dysarthria; the second was to document the phonetic profile of the intelligibility deficit; and the third was to use the results of the phonetic profile to estimate the motor control mechanisms and neurological substrates implicated in Friedreich's ataxia dysarthria.

A quantitative and qualitative evaluation of an automatic occlusion device for tracheoesophageal speech: the Provox FreeHands HME.

This study aimed to evaluate a new automatic tracheostoma valve: the Provox FreeHands HME (manufactured by Atos Medical AB, Sweden). Data from four laryngectomee participants using automatic and also manual occlusion were subjected to acoustic and perceptual analysis. The main results were a significant decrease, from the manual to automatic occlusion condition, in maximum phonation time, mean intensity of read speech and percentage pause time.

Gradient change in the acquisition of phonology.

The prevailing view of phonological development is that changes in pronunciation are driven by phonological changes. This view (it is argued here) derives from the particular form of the data that has most often been used in studies of phonological development, namely broad phonetic transcriptions. Transcribing an earlier pronunciation with one phoneme symbol and a later pronunciation with a different symbol encourages the interpretation that the child has made a flip from one category to another.

The influence of phonemic awareness development on acoustic cue weighting strategies in children's speech perception.

In speech perception, children give particular patterns of weight to different acoustic cues (their cue weighting). These patterns appear to change with increased linguistic experience. Previous speech perception research has found a positive correlation between more analytical cue weighting strategies and the ability to consciously think about and manipulate segment-sized units (phonemic awareness).