The speech aversion hypothesis has explanatory power in a Minimal Speech Approach to aloof, non-verbal, severe autism

In the search for 'pure autism', non-verbal children labeled aloof, Severely Autistic with Developmental Disabilities (ASA/DD), are routinely excluded from psychological research. This exclusion is predicated on the claim that they are indistinguishable from those with SLD/PMLD, which is refuted through a discussion of the extant literature. A novel, falsifiable, speech aversion hypothesis is proposed: "aloof, non-verbal young children (<7 years), with severe autism (CARS≥37), but without significant dysmorphic features, will show aversive reactions to complex speech (>2-3 words), but not to a silent interlocutor, or one imitating their vocalizations, in proximal encounters." Implications are examined by deconstructing the presenting symptoms of ASA/DD in response to the hypothesis. Supporting evidence is drawn from: Minimal Speech Approach (MSA) research showing high levels of spontaneous requests for social routines; a reinterpretation of still-face research as a still-(silent)-face paradigm; auditory processing MMN data employing EEG/MEG; and possible links to epileptiform activity and verbal auditory agnosia. Guidelines are established for future research. This hypothesis, if corroborated, would add to the auditory processing anomalies seen in severe autism and lead to synergies of existing and new areas of research, with significant theoretical, therapeutic, and educational implications.