Educational Implications of Auditory Processing Deficits in Students with High-Functioning Autism Spectrum Disorders

Background:  Reading comprehension and math problem solving difficulties are areas of weakness that impact the academic success of students with higher functioning Autism Spectrum Disorder (HFASD). These academic difficulties are also common to students who suffer from Auditory processing disorders. Imaging studies have reported auditory abnormalities in individuals with autism. Few if any, studies, however, have investigated if auditory abnormities are related to educational difficulties in students with HFASD. 

Objectives:   This issue was addressed by: 1) Examining if 9- to 17-year-old HFASD students display more evidence auditory processing deficits than clinical and typical control samples, 2) Examining if auditory processing was associated with deficits in reading comprehension in the samples of students.     

Methods:  A sample of 138 students in four groups HFASD,  ADHD, HFASD+ADHD symptoms, and typical development participated in this study. (Table 1). ASD symptoms were confirmed with the ADOS (cutoff score > 7) and ADHD symptoms were confirmed with the Conners-3 parent report (cutoff score >70). Audiological processing was assessed with the SCAN-3:C Tests for Auditory Processing Disorders for Children and reading comprehension was assessed as a latent variable assessed with both the Gray Oral Reading Tests-5 (GORT) and the Qualitative Reading Inventory-4 (QRI). 

Results:  A repeated measures MANCOVA with IQ as a covariate for the SCAN subtests [Auditory Figure Ground, Filtered Words, Competing Words Directed Ears, Competing Sentences, Competing Words, and Time Compressed Sentences] revealed a significant Diagnostic Group effect, Wilks Lambda= .66,  F (21,365) = 2.66, p < 001, eta squared = .13.    Pairwise comparisons revealed impairments of the HFASD+ADHD group from the TD and ADHD group on five of the six SCAN measures (see Figure 1). The ASD sample differed from the TD group on four measures but only differed from the ADHD and TD group on Time Compressed Sentences. The HFASD+ADHD group displayed the most consistent pattern of correlations of Reading Comprehension with the SCAN: Auditory Figure Ground r(45) = .43 p < .01, Auditory Reasoning, r(45) = .34 p < .02, Pseudo Word Decoding, r(44) = .33 p < .03,  Competing Words Directed Ear r(43) = .40 p < .01, Auditory Reasoning r(43) = .37 p < .02,  and Recalling Sentences, r(38) = .42 p < .01. ADOS Total Score was also correlated with SCAN Scores in the HFASD and HFASD+ADHD samples, r(44) = -.30 & -.36, p < .05, respectively. 

Conclusions:  This study provides evidence that Auditory Processing deficits may be common in HFASD students, related to ADOS symptoms, and contributes to the academic difficulties experienced by these children in elementary and secondary school. The HFASD+ADHD children displayed the greatest impact of Auditory Processing disturbances. Further research is needed to disentangle the degree to which auditory or attention impairments contribute to the poor SCAN responses in this subgroup of children with HFASD.