I am not an expert with auditory processing disorders; however, I have worked with children with autism for a very long time and know a little about "The Listening Program" which is "treatment" for auditory processing. Occupational Therapists believe strongly in it but I am not sure if research has found this to be an effective treatment. Basically, it is a type of noise therapy that stimulates the brain using classical music, weird sounds, etc. Children can wear the headphones while doing other activities so it is a simple thing you can do at home...if you pay for the program. I think it is very expensive and you may need to be trained on it.
In order to experience what my students were experiencing, I used the listening program on myself at one point. I wore the headphones for the specified time two times a day. I think it improved my ability to filter noise and focus when there is a lot of noise around me. However, I am sure there are many other treatments I am unaware of.
In regards to changing procedures, I have been taught that children with processing disorders need a minimum of 5 seconds to respond to a cue. Then, if they do not respond use a different cue (could be verbal, light touch, a gesture). With that being said, repeating directions/questions to children with processing disorders is only damaging them.
I don't know if any of this will help you at all. I am sure you will get some great advice from doctors.
Here is a link for that program.
The Listening Program- Music-Based Auditory Stimulation® method