My son, meanwhile, has excellent focusing ability, and the more difficult a task is, the more he is able to concentrate (generally speaking - there's the odd exception).
He's an enigma - we've had many different pros disagree as to his diagnoses. Our psychologist has suggested ADHD combined type and Expressive and Receptive language disorder, which is from what I understand the linguistic component of CAPD. Meanwhile he's had four normal hearing tests which have ruled out any ear problems.
Our pediatrician meanwhile disagrees with the ADHD ("I've seen so many kids with ADHD and he's different."). I'm on the fence with the ADHD... some days, sure; others - not a chance. The language processing I believe completely (even with the fact that he reads above grade level in English

)
Anyway.
ADD/ADHD and CAPD can be co-morbid/overlapping much the way that ASD and SPD can be (both of which school staff also thought my son has, but the docs said no way).
I read somewhere (Scientific American Mind, I think), that ADHD and CAPD can have identical symptoms and the diagnosis the child gets sometimes depends on the specialty of the diagnostician (i,e, psychologist Vs. audiologist).
Meanwhile our psychologist said "oh no, he doesn't have CAPD." (She's the one who diagnosed the ADHD). Then in the next breath she admitted that she didn't have all of the testing materials that an audiologist would have (well then how can you say with certainty that it's not CAPD?) Arrgh.
I don't have a problem with her work - I have a problem with testing & diagnosis in general: As my family doctor says, psychology is generally just the practitioner's opinion.
Surely science can do better - you'd think there would be actual medical tests available to pinpoint which brain region(s) is/are deficient. With my layperson's understanding that ADHD lives in the prefrontal cortex while language lives in the left hemisphere, & Broca's & Wernicke's areas, and the primary auditory cortex being located in the temporal lobe, I find the idea that disorders of these areas can be "interchanged by misdiagnosis" really frustrating.
Meanwhile we spend all these hours and dollars just to get someone's opinion...
(sigh)