Maria I. Grigos

Acoustic characterization of the question-statement contrast in 4, 7 and 11 year-old children

Prosodic features of the speech signal include fundamental frequency (F0), intensity and duration. In order to study the development of prosody independent from segmental aspects of speech, we considered the question–statement contrast. In English, adults mark the contrast using changes in fundamental frequency, duration and intensity, with F0 being the most prominent cue. Declarative questions are marked by rising intonation whereas statements are marked by falling intonation. While previous studies have noted that young children can signal this contrast in imitative paradigms, little is known about the acoustic cues children use at different stages in development. The present study sought to provide an acoustic characterization of prosodic cues used by 12 children from three age groups, 4-year-olds, 7-year-olds and 11-year-olds, for elicited productions of declarative statements and questions. Results indicated that 4-year-olds were unable to reliably signal questions using rising fundamental frequency contour. Instead, they used increased final syllable duration to mark questions. Children in the 7-year-old group used all three cues, fundamental frequency, intensity and syllable duration, to contrast questions from statements. The oldest group relied primarily on changes in fundamental frequency and less so on intensity and duration cues. An age-related pattern is evident in that children employ different combinations of acoustic cues to mark the question–statement contrast across development. The impact of motor and cognitive-linguistic complexity on the development of prosodic control is discussed. 2006 Elsevier B.V. All rights reserved.

The relationship between articulatory control and improved phonemic accuracy in childhood apraxia of speech: a longitudinal case study.

Jaw movement patterns were examined longitudinally in a 3-year-old male with childhood apraxia of speech (CAS) and compared with a typically developing control group. The child with CAS was followed for 8 months, until he began accurately and consistently producing the bilabial phonemes /p/, /b/, and /m/. A movement tracking system was used to study jaw duration, displacement, velocity, and stability. A transcription analysis determined the percentage of phoneme errors and consistency. Results showed phoneme-specific changes which included increases in jaw velocity and stability over time, as well as decreases in duration. Kinematic parameters became more similar to patterns seen in the controls during final sessions where tokens were produced most accurately and consistently. Closing velocity and stability, however, were the only measures to fall within a 95% confidence interval established for the controls across all three target phonemes. These findings suggest that motor processes may differ between children with CAS and their typically developing peers.

Oral Articulatory Control in Childhood Apraxia of Speech.

PURPOSE The purpose of this research was to examine spatial and temporal aspects of articulatory control in children with childhood apraxia of speech (CAS), children with speech delay characterized by an articulation/phonological impairment (SD), and controls with typical development (TD) during speech tasks that increased in word length. METHOD The participants included 33 children (11 CAS, 11 SD, and 11 TD) between 3 and 7 years of age. A motion capture system was used to track jaw, lower lip, and upper lip movement during a naming task. Movement duration, velocity, displacement, and variability were measured from accurate word productions. RESULTS Movement variability was significantly higher in the children with CAS compared with participants in the SD and TD groups. Differences in temporal control were seen between both groups of children with speech impairment and the controls with TD during accurate word productions. As word length increased, movement duration and variability differed between the children with CAS and those with SD. CONCLUSIONS These findings provide evidence that movement variability distinguishes children with CAS from speakers with SD. Kinematic differences between the participants with CAS and those with SD suggest that these groups respond differently to linguistic challenges.

Acquisition of articulatory control for sentential focus in children

Abstract The present study examined articulator movement changes associated with the production of sentential focus in 4, 7 and 11-year-old children and adults. A facial capture system was used to track jaw, lower lip and upper lip movements while words were produced with and without focus in phrase-final and non-final positions. Adults produced focused words with significantly greater movement duration, displacement and velocity than unfocused words. Significant differences in duration, displacement and velocity between focused and unfocused productions were seen in the 7 and 11 year olds, although these results were not as consistent as those seen in the adults. Articulator movement differences between focused and unfocused words were seen in both the phrase-final and non-final positions in adults yet only in the phrase-final position in children. Findings suggest that children begin to modify articulator movement to mark sentential focus between 7 and 11 years of age and are likely to continue to refine movement patterns for this prosodic task throughout adolescence.

Nonword Repetition and Speech Motor Control in Children.

This study examined how familiarity of word structures influenced articulatory control in children and adolescents during repetition of real words (RWs) and nonwords (NWs). A passive reflective marker system was used to track articulator movement. Measures of accuracy were obtained during repetition of RWs and NWs, and kinematic analysis of movement duration and variability was conducted. Participants showed greater consonant and vowel accuracy during RW than NW repetition. Jaw movement duration was longer in NWs compared to RWs across age groups, and younger children produced utterances with longer jaw movement duration compared to older children. Jaw movement variability was consistently greater during repetition of NWs than RWs in both groups of participants. The results indicate that increases in phonological short-term memory demands affect articulator movement. This effect is most pronounced in younger children. A range of skills may develop during childhood, which supports NW repetition skills.

Articulatory Control in Childhood Apraxia of Speech in a Novel Word–Learning Task

Purpose Articulatory control and speech production accuracy were examined in children with childhood apraxia of speech (CAS) and typically developing (TD) controls within a novel word-learning task to better understand the influence of planning and programming deficits in the production of unfamiliar words. Method Participants included 16 children between the ages of 5 and 6 years (8 CAS, 8 TD). Short- and long-term changes in lip and jaw movement, consonant and vowel accuracy, and token-to-token consistency were measured for 2 novel words that differed in articulatory complexity. Results Children with CAS displayed short- and long-term changes in consonant accuracy and consistency. Lip and jaw movements did not change over time. Jaw movement duration was longer in children with CAS than in TD controls. Movement stability differed between low- and high-complexity words in both groups. Conclusions Children with CAS displayed a learning effect for consonant accuracy and consistency. Lack of change in movement stability may indicate that children with CAS require additional practice to demonstrate changes in speech motor control, even within production of novel word targets with greater consonant and vowel accuracy and consistency. The longer movement duration observed in children with CAS is believed to give children additional time to plan and program movements within a novel skill.

Changes in movement transitions across a practice period in childhood apraxia of speech

ABSTRACT This study examined changes in speech motor control across a movement transition between sounds within a motor learning task in children with apraxia of speech (CAS) and typical development (TD). It was investigated whether oral articulator movement was refined with practice and whether practice gains generalized to words not included in the practice session. A total of 16 children (ages 5–6) with CAS (n = 8) and TD (n = 8) participated in this study. Novel and real word tokens were produced at three time points. Kinematic data was collected using facial motion tracking at each time point. Children completed a practice session following baseline data collection session that integrated motor learning principles. Three tokens were included in the practice session and the remaining stimuli assessed carryover of practice gains. Kinematic data was then collected immediately following practice and 3 days later. Kinematic analyses were conducted on the movement gesture for the first syllable of each word. Narrow transcription analyses examined speech production accuracy. Children in the CAS group displayed increased consonant and vowel accuracy only for the practised tokens. Adjustments to spatial control and movement variability were observed in the CAS group, though only for practised words. Children in the TD group altered spatial and temporal domains of movement and variability across both practised and non-practised tokens. Interestingly, the CAS group displayed a pattern of increased displacement along with decreased variability, which was not observed in the TD group. The degree to which these findings reflect facilitative or maladaptive changes are discussed. Results are also interpreted in relation to vowel properties, novel/real word status and variable practice of novel and real words.

Investigating the Use of a Nonspeech Task to Measure Tongue–Jaw Differentiation: Findings Across Typical Development

Purpose Clinically, a task of alternating tongue lateralization has been used to evaluate the ability to independently control the tongue and jaw, with jaw movement interpreted as a sign of poor tongue-jaw differentiation. However, there is a lack of normative data regarding jaw movement during this task and whether this changes over the course of development. This study quantified relative tongue and jaw movement during alternating tongue lateralization for typical speakers across age ranges and examined whether degree of jaw movement varies as a function of age. Method Participants were 39 typical children, adolescents, and adults ranging from 6 to 29 years old. A motion capture system was used to track tongue and jaw movement during an alternating tongue lateralization task, and the average relative contribution of the jaw to tongue lateralization was determined for each participant. Results Age did not correlate significantly with the average relative contribution of the jaw to tongue lateralization. Typical children, adolescents, and adults exhibited wide variability in the degree of jaw movement during this task. Conclusion Variability among typical speakers in alternating tongue lateralization performance makes it challenging to determine if/when performance should be considered atypical. Clinical findings from this task must be interpreted with caution. Supplemental Material https://doi.org/10.23641/asha.6626222.

Acoustics of contrastive prosody in children

Empirical data on the acoustics of prosodic control in children is limited, particularly for linguistically contrastive tasks. Twelve children aged 4, 7, and 11 years were asked to produce two utterances ‘‘Show Bob a bot’’ (voiced consonants) and ‘‘Show Pop a pot’’ (voiceless consonants) 10 times each with emphasis placed on the second word (Bob/Pop) and 10 times with emphasis placed on the last word (bot/pot). A total of 40 utterances were analyzed per child. The following acoustic measures were obtained for each word within each utterance: average fundamental frequency (f0), peak f0, average intensity, peak intensity, and duration. Preliminary results suggest that 4 year olds are unable to modulate prosodic cues to signal the linguistic contrast. The 7 year olds, however, not only signaled the appropriate stress location, but did so with the most contrastive differences in f0, intensity, and duration, of all age groups. Prosodic differences between stressed and unstressed words were more pronounced for ...

Acoustic correlates of the question–statement contrast in children

The acoustics of prosodic control in children was studied in 4‐, 7‐, and 11‐year olds using the question–statement contrast. Each child produced the utterances ‘‘Show Bob a bot’’ (voiced consonants) and ‘‘Show Pop a pot’’ (voiceless consonants) ten times each as a question and ten times each as a statement. A total of 40 utterances were analyzed per child. The following acoustic measures were obtained for each word within each utterance: average fundamental frequency (f0), peak f0, slope of f0, average intensity, peak intensity and duration. Preliminary results indicate no significant difference between questions and statements for 4‐year olds in both the voiced and voiceless consonant conditions. In contrast, 7‐ and 11‐year olds differentiated questions from statements by increasing average, peak, and slope of f0 as well as increasing the duration of the final syllable. Changes in syllable duration between questions and statements were more pronounced for the utterance with voiced consonants. These findi...