Abstract
Autism Spectrum Disorders (ASD) represent a heterogeneous group of disorders, with onset in developmental age, which present a clinical expressiveness that varies from subject to subject and in the same subject over time. The DSM 5 defines Autism Spectrum Disorders according to two main criteria: persistent deficits in social communication and social interaction in multiple contexts and limited and repetitive patterns of behavior, interests or activities. This disorder can manifest itself across a broad spectrum of severity levels. Indeed, ASD includes clinical conditions from low functioning (LF-Low Functioning) to high functioning (HF-High Functioning), taking cognitive and adaptive functioning as a reference. One of the main characteristics of individuals with ASD is a delay in receptive and expressive communication. These deficits have led to the identification of evidence-based practices, particularly for those with severe communication difficulties. Augmentative Alternative Communication (AAC) has been implemented to compensate for deficits in functional communication and language skills in individuals with complex communication deficits. The AAC comprises communication systems including the Manual Signs, speech and image output devices (Communicators), and Image Exchange Systems (PECS); these systems have been shown to actually improve various abilities in autism such as social skills, modify and improve dysfunctional behaviors and, above all, improve learning. Recent meta-analyses have shown how PECS and Manual Sign can have great effects on the communication skills of young people with autism. The aim of this study is to compare these two types of intervention to improve communication in terms of vocalization in subjects with ASD and try to understand which of the two lead to more significant and rapid improvements.