Earlier identification of children with autism spectrum disorder: An automatic vocalisation-based approach

Copyright © 2017 ISCA. Autism spectrum disorder (ASD) is a neurodevelopmental disorder usually diagnosed in or beyond toddlerhood. ASD is defined by repetitive and restricted behaviours, and deficits in social communication. The early speech-language development of individuals with ASD has been characterised as delayed. However, little is known about ASD-related characteristics of pre-linguistic vocalisations at the feature level. In this study, we examined pre-linguistic vocalisations of 10-month-old individuals later diagnosed with ASD and a matched control group of typically developing individuals (N = 20). We segmented 684 vocalisations from parent-child interaction recordings. All vocalisations were annotated and signal-analytically decomposed. We analysed ASD-related vocalisation specificities on the basis of a standardised set (eGeMAPS) of 88 acoustic features selected for clinical speech analysis applications. 54 features showed evidence for a differentiation between vocalisations of individuals later diagnosed with ASD and controls. In addition, we evaluated the feasibility of automated, vocalisation-based identification of individuals later diagnosed with ASD.We compared linear kernel support vector machines and a 1-layer bidirectional long short-term memory neural network. Both classification approaches achieved an accuracy of 75% for subject-wise identification in a subject-independent 3-fold cross-validation scheme. Our promising results may be an important contribution en-route to facilitate earlier identification of ASD

The lexicon in narratives – an investigation of lexical skills during story-telling in children with and without language impairment

<p>Background: After the acquisition of basic grammatical skills, narrative competence gradually develops in preschool and primary school age, including the subsequent elaboration of syntactic complexity and the use cohesive elements. In addition, the adequate use of lexical means is an important component of story-telling. Previous research has shown children with language impairment have substantial difficulty when telling stories. Their deficits affect both the microstructural and the macrostructural level. Since lexical competence is relevant for narrative competence and lexical problems are often part of language impairment, the present study investigates the quantity, diversity, and composition of the lexicon in oral narratives.</p> <p>Method: The first, cross-sectional study includes 100 monolingual, typically developing (TD), German-speaking children at age 3;0-6;0. The children narrated three picture stories. The number of types, tokens, types-token ratio, mean length of utterance (MLU) and lexical composition were analysed. Results demonstrate that vocabulary size, as well as lexical composition, did not change over time, while lexical diversity and MLU increased with age. In study 2, a comparison of 34 children with language impairment (LI) and 34 age-matched TD children from study 1 shows a limited lexical diversity and a significantly lower MLU for children with LI. Children with LI used more nouns and more personal-social words, but fewer pronouns.</p> <p>Discussion: Vocabulary size and the use of word categories in children with LI are broadly similar to that of TD children. However, oral narratives of children with LI are characterized by a limited lexical diversity and shorter utterances. In addition, subtle differences with respect to the use of word categories were found, which are more typical for earlier phases of language development.</p

Typical vs. atypical: Combining auditory Gestalt perception and acoustic analysis of early vocalisations in Rett syndrome

© 2018 Elsevier Ltd Background: Early speech-language development of individuals with Rett syndrome (RTT) has been repeatedly characterised by a co-occurrence of apparently typical and atypical vocalisations. Aims: To describe specific features of this intermittent character of typical versus atypical early RTT-associated vocalisations by combining auditory Gestalt perception and acoustic vocalisation analysis. Methods and procedures: We extracted N = 363 (pre-)linguistic vocalisations from home video recordings of an infant later diagnosed with RTT. In a listening experiment, all vocalisations were assessed for (a)typicality by five experts on early human development. Listeners’ auditory concepts of (a)typicality were investigated in context of a comprehensive set of acoustic time-, spectral- and/or energy-related higher-order features extracted from the vocalisations. Outcomes and results: More than half of the vocalisations were rated as ‘atypical’ by at least one listener. Atypicality was mainly related to the auditory attribute ‘timbre’ and to prosodic, spectral, and voice quality features in the acoustic domain. Conclusions and implications: Knowledge gained in our study shall contribute to the generation of an objective model of early vocalisation atypicality. Such a model might be used for increasing caregivers’ and healthcare professionals’ sensitivity to identify atypical vocalisation patterns, or even for a probabilistic approach to automatically detect RTT based on early vocalisations