This sounds familiar. Ds8 has APD. I brought him to a speech therapist who proceeded to give him the generalized approach to treating CAPD, ie, giving him word pairs and asking which sounds the same or different, questions that relate to auditory memory etc. According to her, he scores around 40% with her. When I did similar work with him (part of the program is for continued practice at home), he scored a 100% each time. I even tried the more advanced sections of the book she said he wasnt ready for. It didn't matter- he still got 100% or nearly there. I asked him why and he said he's just so used to my voice, but he's not familiar with hers.
Kriston, does your son attend any external classes? What does the teacher say? I had had one or two comments that ds would volunteer unrelated information, but I didn't think much of it till the diagnosis.
