Effects of Syllable Position, Fundamental Frequency, Duration and Amplitude on Word Stress in Mandarin Chinese.

This study examined the importance of syllable position, duration, and tone/pitch for the assignment of stress in Chinese hums. Twenty native Mandarin speakers and 20 native English speakers were asked to assign primary stress to two-syllable Chinese hums. The importance of acoustic cues for stress assignment was also evaluated. Our findings indicate that syllable position plays the most prominent role in stress assignment. Native Chinese listeners preferred to assign stress to final syllables whereas native English listeners preferred to assign stress to initial syllables. Both language groups were sensitive to different acoustic cues in assigning stress. The effects of complex interactions of syllable position, tone, duration and intensity on stress assignment in Chinese hums for both language groups support the hypothesis that linguistic experience affects speech perception at the suprasegmental level.

Effects of Age, Sex and Syllable Number on Voice Onset Time: Evidence from Children's Voiceless Aspirated Stops.

Voice onset time (VOT) is a temporal acoustic parameter that reflects motor speech coordination skills. This study investigated the patterns of age and sex differences across development of voice onset time in a group of 70 English-speaking children, ranging in age from 4.1 to 18.4 years, and 12 young adults. The effect of the number of syllables on VOT patterns was also examined. Speech samples were elicited by producing syllables /pa/ and /pataka/. Results supported previous findings showing that younger children produce longer VOT values with higher levels of variability. Markedly higher VOT values and increased variability were found for boys at ages between 8 and 11 years, confirming sex differences in VOT patterns and patterns of variability. In addition, all participants consistently produced shorter VOT with higher variability for multisyllables than monosyllables, indicating an effect of syllable number. Possible explanations for these findings and clinical implications are discussed.

Age-related sex differences in language lateralization: A magnetoencephalography study in children.

It is well supported by behavioral and neuroimaging studies that typical language function is lateralized to the left hemisphere in the adult brain and this laterality is less well defined in children. The behavioral literature suggests there maybe be sex differences in language development, but this has not been examined systematically with neuroimaging. In this study, magnetoencephalography was used to investigate the spatiotemporal patterns of language lateralization as a function of age and sex. Eighty typically developing children (46 female, 34 male; 4-18 years) participated in an overt visual verb generation task. An analysis method called differential beamforming was used to analyze language-related changes in oscillatory activity referred to as low-gamma event-related desynchrony (ERD). The proportion of ERD over language areas relative to total ERD was calculated. We found different patterns of laterality between boys and girls. Boys showed left-hemisphere lateralization in the frontal and temporal language-related areas across age groups, whereas girls showed a more bilateral pattern, particularly in frontal language-related areas. Differences in patterns of ERD were most striking between boys and girls in the younger age groups, and these patterns became more similar with increasing age, specifically in the preteen years. Our findings show sex differences in language lateralization during childhood; however, these differences do not seem to persist into adulthood. We present possible explanations for these differences. We also discuss the implications of these findings for presurgical language mapping in children and highlight the importance of examining the question of sex-related language differences across development.

Changes in voice onset time and motor speech skills in children following motor speech therapy: Evidence from /pa/ productions.

This study evaluated changes in motor speech control and inter-gestural coordination for children with speech sound disorders (SSD) subsequent to Prompts for Restructuring Oral and Muscular Phonetic Targets (PROMPT) intervention. We measured the distribution patterns of voice onset time (VOT) for a voiceless stop (/p/) to examine the changes in inter-gestural coordination. Two standardized tests were used (Verbal Motor Production Assessment for Children (VMPAC), GFTA-2) to assess the changes in motor speech skills and articulation. Data showed positive changes in patterns of VOT with a lower pattern of variability. All children showed significantly higher scores for VMPAC, but only some children showed higher scores for GFTA-2. Results suggest that the proprioceptive feedback provided through PROMPT had a positive influence on speech motor control and inter-gestural coordination in voicing behavior. This set of VOT data for children with SSD adds to our understanding of the speech characteristics underlying speech motor control. Directions for future studies are discussed.

Relationship between speech motor control and speech intelligibility in children with speech sound disorders.

UNLABELLED: The current study was undertaken to investigate the impact of speech motor issues on the speech intelligibility of children with moderate to severe speech sound disorders (SSD) within the context of the PROMPT intervention approach. The word-level Children's Speech Intelligibility Measure (CSIM), the sentence-level Beginner's Intelligibility Test (BIT) and tests of speech motor control and articulation proficiency were administered to 12 children (3:11 to 6:7 years) before and after PROMPT therapy. PROMPT treatment was provided for 45 min twice a week for 8 weeks. Twenty-four naïve adult listeners aged 22-46 years judged the intelligibility of the words and sentences. For CSIM, each time a recorded word was played to the listeners they were asked to look at a list of 12 words (multiple-choice format) and circle the word while for BIT sentences, the listeners were asked to write down everything they heard. Words correctly circled (CSIM) or transcribed (BIT) were averaged across three naïve judges to calculate percentage speech intelligibility. Speech intelligibility at both the word and sentence level was significantly correlated with speech motor control, but not articulatory proficiency. Further, the severity of speech motor planning and sequencing issues may potentially be a limiting factor in connected speech intelligibility and highlights the need to target these issues early and directly in treatment. LEARNING OUTCOMES: The reader will be able to: (1) outline the advantages and disadvantages of using word- and sentence-level speech intelligibility tests; (2) describe the impact of speech motor control and articulatory proficiency on speech intelligibility; and (3) describe how speech motor control and speech intelligibility data may provide critical information to aid treatment planning.

A cross-language study of perception of lexical stress in English.

This study investigates the question of whether language background affects the perception of lexical stress in English. Thirty native English speakers and 30 native Chinese learners of English participated in a stressed-syllable identification task and a discrimination task involving three types of stimuli (real words/pseudowords/hums). The results show that both language groups were able to identify and discriminate stress patterns. Lexical and segmental information affected the English and Chinese speakers in varying degrees. English and Chinese speakers showed different response patterns to trochaic vs. iambic stress across the three types of stimuli. An acoustic analysis revealed that two language groups used different acoustic cues to process lexical stress. The findings suggest that the different degrees of lexical and segmental effects can be explained by language background, which in turn supports the hypothesis that language background affects the perception of lexical stress in English.