Intelligibility of degraded speech and the relationship between symptoms of inattention, hyperactivity/impulsivity and language impairment in children with suspected auditory processing disorder

Objectives: To compare the sensitivity and specificity of Auditory Figure Ground sub-tests of the SCAN-3 battery, using signal to noise ratio (SNR) of +8 dB (AFG+8) and 0 dB (AFGO), in identifying auditory processing disorder (APD). A secondary objective was to evaluate any difference in auditory processing (AP) between children with symptoms of inattention versus combined sub-types of Attention Deficit Hyperactivity Disorder (ADHD). Methods: Data from 201 children, aged 6 to 16 years (mean: 10 years 6 months, SD: 2 years 8 months), who were assessed for suspected APD were reviewed retrospectively. The outcomes of the SCAN-3 APD test battery, Swanson Nolan and Pelham-IV parental rating (SNAP-IV) and Children's Communication Checklist-2 (CCC-2) were analysed. Results: AFGO had a sensitivity of 56.3% and specificity of 100% in identifying children performing poorly in at least two of six SCAN-3 sub-tests or one of the two questionnaires, in contrast to 42.1% and 80% respectively for AFG+8. Impaired AP was mostly associated with symptoms of ADHD and/or language impairment (LI). LI was present in 92.9% of children with ADHD symptoms. Children with symptoms of combined ADHD plus LI performed significantly poorly (p < 0.05) compared to inattention ADHD plus LI in Filtered Words (FW) sub-test, but not in the rest of the SCAN-3 sub-tests. Conclusion: Speech in noise tests using SNR of 0 dB is better than +8 dB in assessing APD. The better FW performance of the inattention ADHD plus LI group can be speculated to be related to known difference in activity in a neural network between different sub-types of ADHD. The findings of the study and existing literature suggest that neural networks connecting the cerebral hemispheres, basal ganglia and cerebellum are involved in APD, ADHD and LI. (C) 2017 Elsevier B.V. All rights reserved.