Abstract
Children with neurodevelopmental disorders have a high rate of listening difficulties, but despite decades of research, the relation between these conditions remains unclear. Using resting state fMRI to image the child's brain noninvasively, we investigate the distribution of speech, non-speech 'sound', and visual processing networks in the forebrain, and examine a cross-section of age differences within these networks in children (6-14 years old) with normal hearing, including typically developing children, children with listening difficulties (LiD), and children with attention-deficit/hyperactivity disorder (ADHD). Relative to typically developing children, a reduction in functional connectivity of the speech network was found in children with LiD. No reduction was found in connections processing non-speech sounds or visual stimuli in the children with LiD, suggesting a specific deficit in speech processing. A second group of children diagnosed with ADHD showed reduced connectivity in both speech and sound networks, but not in the visual network, suggesting a common underlying cause for auditory and speech difficulties in the auditory system of children with ADHD. We conclude that listening difficulties in children are mediated by speech-specific neural mechanisms. The findings strengthen research calls for obligatory speech intelligibility testing under challenging listening conditions (noise, reverberation) as a component of clinical pediatric audiological assessment.