His word-level decoding scores are pretty good. I actually meant some of the clinical scores that have to do with how quickly he read those words. (You probably don't have those, so don't worry about searching for them.) We can get similar information from the GORT and ORF data, but for connected text, rather than single words. Those measures consistently indicate lower fluency than decoding, in the average range, with comprehension tracking fluency (not surprisingly).
CAPD wouldn't necessarily show up on auditory tests, if they are of acuity, rather than perception. You would need an eval by an audiologist. And the challenge with audiobooks is that if his auditory processing actually is an issue, he might not get more out of text by listening than reading. Additionally, if the comprehension relative weaknesses have their origins in ADHD, audiobooks probably won't help much over reading, although in-person read-aloud may, because of the interaction with the reader. Do you have a listening comp score from the WIAT? Preferably the Oral Discourse Comprehension component score. If text-to-speech is going to be helpful, I usually look for a higher ODC component score than RC subtest score. If it's similar or weaker, that suggests there's not a lot of incremental gain to audiotext.
As to diagnostic criteria: the field doesn't really use hard-and-fast point differences, especially when comparing instruments that are not co-normed or normatively-linked. Also, I should note that his math achievement is a bit higher than would be predicted based on his FSIQ, which suggests that sorting out some of the items in the diagnostic discussion should be a priority, as his measured FSIQ may not be fully representative of his ability.
