The goal of the study is to identify the speech features that are necessary and sufficient to assess the psychophysiological and neurological status of the informant. Participants in the study were 45 children with autism spectrum disorders (ASD), 20 children with Down syndrome (DS) biologically aged 5-16 years, and 300 typical development (TD) coevals. The acoustic, perceptual, and phonetic analysis were conducted. The speech of TD children is characterized by words, simple and complex phrases; the speech of ASD children is predominantly represented by simple words and simple phrases, syllables, vocalizations, speech-like constructions, repetitions of a part of an adult’s speech, echolalia, and children with DS use simple words and simple phrases with fuzzy articulation. For all children with ASD voice and speech are characterized by high values of pitch, pitch range, abnormal spectrum, and well-marked high-frequency. We found significant differences of these acoustic features between ASD and TD children and children with DS in spontaneous speech. The speech of children with DS is characterized by a longer duration of words and stressed vowels in words, low values of pitch and third formant, a large number of unformed consonant phonemes vs. speech of TD and ASD children. We believe that the identified acoustic characteristics of the speech of children can be used in the diagnosis of the disease, and for ASD children to serve as biomarkers of autism.
The study was supported by the Russian Science Foundation (project 18-18-00063).