Acoustic and Perceptual Measurement of Expressive Prosody in High-Functioning Autism: Increased Pitch Range and What it Means to Listeners

Abstract

Are there consistent markers of atypical prosody in speakers with high functioning autism (HFA) compared to typically-developing speakers? We examined: (1) acoustic measurements of pitch range, mean pitch and speech rate in conversation, (2) perceptual ratings of conversation for these features and overall prosody, and (3) acoustic measurements of speech from a structured task. Increased pitch range was found in speakers with HFA during both conversation and structured communication. In global ratings listeners rated speakers with HFA as having atypical prosody. Although the HFA group demonstrated increased acoustic pitch range, listeners did not rate speakers with HFA as having increased pitch variation. We suggest that the quality of pitch variation used by speakers with HFA was non-conventional and thus not registered as such by listeners.

The Tilt Model Acoustic Survey of Intonation in Children with Severe Autism

“…6, No. 4;2016 In these tables we used s and q after duration, amplitude and tilt s and q being abbreviations for statements and questions. The number (N) of the autistic children who could produce the questions was 14.…”

“…6, No. 4;2016 intonation and the Tilt Model of Intonation, which provided a complete mapping between acoustics and phonology and an exact acoustic analysis, were used. In the first statistic hypothesis, the durations of statements and questions were surveyed, and the result in Table 1 indicated that there is no significant difference in the two kinds of sentences between the two groups.…”

“…6, No. 4;2016 exclamatory in order to indicate whether children with autism produce these types of sentences with a monotone intonation or not.…”

“…Other measures of intonation including amplitude, duration, and location of pitch peak revealed defects that are more complex than predicted. Nadig & Shaw (2011) found out that the children with HFA have a significantly larger pitch range during both conversation and structured communication. Simmons & Baitaxe (1975) mention that autistic children don't have the ability to ask questions in the form of a typical question.…”

Speaking Fundamental Frequency and Individual Variability in Caucasian and African American School-Age Children

“…It has been suggested that children with childhood apraxia of speech may demonstrate "reduced range of or variable (perceived) pitch, as well as reduced range of or variable (perceived) loudness, (which) gives the listener the impression of monotone, monoloud speech, respectively" (American Speech-Hearing-Language Association, 2007, p. 20). Prosodic disturbances have also been noted in the speech of children with high-functioning autism; specifically, greater SFF range in conversational speech compared to typically developing peers (Nadig & Shaw, 2012). Considering all of the disorders that may involve abnormal measured or perceived vocal variability, objective data on frequency variability in typically developing children may help the speech-language pathologist in diagnosing and tracking changes in children with a variety of communication disorders.…”