REVIEW PAPER Improved Signal-to-Noise Ratio and Classroom Performance in Children with Autism Spectrum Disorder: a Systematic Review Yolanda van der Kruk 1,2 & Wayne J. Wilson 1,2 & Kelsey Palghat 1,2 & Cerys Downing 1,2 & Keely Harper-Hill 1,3 & Jill Ashburner 1,4 Received: 24 January 2017 /Accepted: 25 July 2017 # Springer Science+Business Media, LLC 2017 Abstract Purpose This paper systematically reviews the literature to determine if improving the signal-to-noise ratio (SNR) im- proves classroom performance in students with autism spec- trum disorder (ASD). Methods Six databases were searched for the terms acoustics, signal-to-noise ratio, classroom and ASD. Five studies were found that met the selection criteria. Results All five studies reported improving the SNR benefit- ted students with ASD in the classroom. Benefits included improved listening behaviours, increased on-task behaviours, improved speech recognition and reduced listening stress. Conclusion The evidence is suggestive that improving the SNR improves classroom performance in students with ASD. Limitations included the small number of studies and limited range of technologies considered. Further research should consider other technologies that could mitigate tactile sensitivities present in some students with ASD. Keywords Signal-to-noise ratio (SNR) . Frequency modulation (FM) . Soundfield amplification (SFA) . Classroom acoustics . Autism spectrum disorder (ASD) Description and Prevalence of Autism Spectrum Disorder Autism spectrum disorder (ASD) is a set of complex neurodevelopmental disorders characterized by impairments in social-communication skills combined with repetitive and restricted behaviours and interests (American Psychiatric Association 2013). The proposed prevalence of ASD has re- cently undergone some challenges with a change in the diag- nostic criteria for the disorder from the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision (DSM-IV-TR)(American Psychiatric Association 2000) to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-V)(American Psychiatric Association 2013). As defined by the relevant version of the DSM, ASD has been reported to affect approximately one in 68 children in the USA (Christensen et al. 2016). Estimates of prevalence rates in the United Kingdom have fluctuated from 1 in 116 (Baird et al. 2006) to 1 in 64 (Baron-Cohen et al. 2009), and in Australia from 1 in 280 to 1 in 826 (Williams et al. 2008) to 1 in 119 (Barbaro and Dissanayake 2010). Similar rates have been reported in other countries with studies in Asia, Europe and North America reporting average prevalences of between 1 and 2% (Centers for Disease Control and Prevention 2014). ASD prevalence has consistently shown a strong male bias (e.g. 1 in 42 in males compared to 1 in 189 in females) and has been found to occur in all ethnic, racial and socioeconomic groups (Christensen et al. 2016). Due to the heterogeneity of its symptom severity, ASD is considered a ‘spectrum disorder’ consisting of different levels of impairment in two general areas in the DSM-V (American Psychiatric Association 2013). The first area is social commu- nication and interaction. This can include deficits in social- emotional reciprocity; nonverbal communicative behaviours and/or developing, maintaining and understanding * Yolanda van der Kruk y.kerlenvanderkruk@uq.net.au 1 Cooperative Research Centre for Living with Autism (Autism CRC), Brisbane, Australia 2 School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, QLD 4072, Australia 3 School of Cultural and Professional Learning, Queensland University of Technology, Brisbane, Australia 4 Autism Queensland, Brisbane, Australia Rev J Autism Dev Disord DOI 10.1007/s40489-017-0111-7