Autism spectrum disorder (ASD) is a neurodevelopmental disorder often associated with difficulties in speech production and fine-motor tasks. Thus, there is a need to develop objective measures to assess and understand speech production and other fine-motor challenges in individuals with ASD. In addition, recent research suggests that difficulties with speech production and fine-motor tasks may contribute to language difficulties in ASD. In this paper, we explore the utility of an off-body recording platform, from which we administer a speech- and fine-motor protocol to verbal children with ASD and neurotypical controls. We utilize a correlation-based analysis technique to develop proxy measures of motor coordination from signals derived from recordings of speech- and fine-motor behaviors. Eigenvalues of the resulting correlation matrix are inputs to Gaussian Mixture Models to discriminate between highly-verbal children with ASD and neurotypical controls. These eigenvalues also characterize the complexity (underlying dimensionality) of representative signals of speech- and fine-motor movement dynamics, and form the feature basis to estimate scores on an expressive vocabulary measure. Based on a pilot dataset (15 ASD and 15 controls), features derived from an oral story reading task are used in discriminating between the two groups with AUCs > 0.80, and highlight lower complexity of coordination in children with ASD. Features derived from handwriting and maze tracing tasks led to AUCs of 0.86 and 0.91, however features derived from ocular tasks did not aid in discrimination between the ASD and neurotypical groups. In addition, features derived from free speech and sustained vowel tasks are strongly correlated with expressive vocabulary scores. These results indicate the promise of a correlation-based analysis in elucidating motor differences between individuals with ASD and neurotypical controls.

Nonverbal vocalizations contain important affective and communicative information, especially for those who do not use traditional speech, including individuals who have autism and are non- or minimally verbal (nv/mv). Although these vocalizations are often understood by those who know them well, they can be challenging to understand for the community-at-large. This work presents (1) a methodology for collecting spontaneous vocalizations from nv/mv individuals in natural environments, with no researcher present, and personalized in-the-moment labels from a family member; (2) speaker-dependent classification of these real-world sounds for three nv/mv individuals; and (3) an interactive application to translate the nonverbal vocalizations in real time. Using support-vector machine and random forest models, we achieved speaker-dependent unweighted average recalls (UARs) of 0.75, 0.53, and 0.79 for the three individuals, respectively, with each model discriminating between 5 nonverbal vocalization classes. We also present first results for real-time binary classification of positive- and negative-affect nonverbal vocalizations, trained using a commercial wearable microphone and tested in real time using a smartphone. This work informs personalized machine learning methods for non-traditional communicators and advances real-world interactive augmentative technology for an underserved population.