Behavioral and physiological responses to child-directed speech of children with autism spectrum disorders or typical development.

Young boys with autism were compared to typically developing boys on responses to nonsocial and child-directed speech (CDS) stimuli. Behavioral (looking) and physiological (heart rate and respiratory sinus arrhythmia) measures were collected. Boys with autism looked equally as much as chronological age-matched peers at nonsocial stimuli, but less at CDS stimuli. Boys with autism and language age-matched peers differed in patterns of looking at live versus videotaped CDS stimuli. Boys with autism demonstrated faster heart rates than chronological age-matched peers, but did not differ significantly on respiratory sinus arrhythmia. Reduced attention during CDS may restrict language-learning opportunities for children with autism. The heart rate findings suggest that young children with autism have a nonspecific elevated arousal level.

Phonological accuracy and intelligibility in connected speech of boys with fragile X syndrome or Down syndrome.

PURPOSE: To compare the phonological accuracy and speech intelligibility of boys with fragile X syndrome with autism spectrum disorder (FXS-ASD), fragile X syndrome only (FXS-O), Down syndrome (DS), and typically developing (TD) boys. METHOD: Participants were 32 boys with FXS-O (3-14 years), 31 with FXS-ASD (5-15 years), 34 with DS (4-16 years), and 45 TD boys of similar nonverbal mental age. We used connected speech samples to compute measures of phonological accuracy, phonological process occurrence, and intelligibility. RESULTS: The boys with FXS, regardless of autism status, did not differ from TD boys on phonological accuracy and phonological process occurrence but produced fewer intelligible words than did TD boys. The boys with DS scored lower on measures of phonological accuracy and occurrence of phonological processes than all other groups and used fewer intelligible words than did TD boys. The boys with FXS and the boys with DS did not differ on measures of intelligibility. CONCLUSIONS: Boys with FXS, regardless of autism status, exhibited phonological characteristics similar to those of younger TD children but were less intelligible in connected speech. Boys with DS showed greater delays in all phonological measures than the boys with FXS and the TD boys.

Effects of altered fundamental frequency on nasalance during vowel production by adult speakers at targeted sound pressure levels.

OBJECTIVE: This study investigated the effects of altered fundamental frequency (F0) on nasalance levels of the vowels /i/ and /a/ produced by adults without cleft palate within a controlled sound pressure level (SPL) range. DESIGN: A prospective group design with convenience sampling from the University of North Carolina at Chapel Hill was used. PARTICIPANTS: 20 men and 20 women participated, aged 18 to 55 years. All were native English speakers with normal speech and language skills and adequate velopharyngeal function. MAIN OUTCOME MEASURES: The outcome measures were percentage nasalance obtained from the Nasometer 6200 (KayPentax) headset and the Computerized Speech Lab Model 4400 (CSL, KayPentax) during vowel production while speakers (1) targeted an SPL range of 75 to 85 dB and (2) targeted the SPL plus F0 range of 165 to 175 Hz. RESULTS: A significant univariate effect was found for the vowels /i/ and /a/ in the targeted SPL condition such that /i/ was produced with higher nasalance than /a/. A significant univariate effect was also found during production of /a/ in the targeted SPL plus F0 condition such that men produced /a/ with higher nasalance than women did. CONCLUSIONS: SPL appears to largely account for percentage nasalance differences between the vowels /i/ and /a/ produced by adult male and female speakers. Increased F0 by male speakers appears to influence percentage nasalance during production of the vowel /a/. Clinical implications in regard to assessment of hypernasality are discussed.