Well, he's already been diagnosed with Down Syndrome and Seizure Disorder, so qualifies for speech and other therapies anyway.
In the beginning, the school told us he didn't qualify for speech therapy. Huh? He doesn't speak! How can he not qualify? Well, it had something to do with their testing showed that his "expressive" speech and "receptive" speech were at the same levels. In other words, in their minds, he wasn't speaking because he was too cognitively impaired to understand language, let alone speak it. So...I had to go home and video tape our little guy going through his day -- following directives...such as "open the drawer and get out your swim suit" and..."go get "The Cat in the Hat" (which he successfully retrieved from a box of books and toys - that book being on the very bottom -- anyway, we called another IEP, and we had to prove that he did indeed understand language...so finally we got him into speech therapy at school for 1 hour a week (and that got bumped up to 1 1/2 hours this past semester). However, the speech therapy wasn't so much geared for producing speech -- it was more like showing 3 different items and having him select the right one, or rolling a ball back and forth to show him that in conversation we take turns (well, doesn't one have to be able to speech before they have conversation???) So...anyway, IEP #3 we proposed that producing 20 spoken words (or word approximations) actually be put on the IEP -- we actually had an IEP meeting that stretched out for 3 1/2 weeks, because I wasn't budging, and they didn't want to put that on there. But we brought in documentation from his Epileptologist and other specialists...and finally got it on there, so that speech therapy at school was actually focused on producing speech.
We did also take him to outside speech therapy, and using music and motion seemed to help in the beginning, but then for some reason his therapist abandoned that tactic, and seemed to spend 25 minutes of his 30 minute therapy sessions in behavior management (making him sit in his chair, waiting for him to comply with a directive, etc.).
Beth Israel hospital/Harvard U has been doing some ground breaking research into getting older autistic kids (older than 5) to speak again using tuned drums and the child hits the drums while the words are chanted...anyway, they have had success with their initial small trial in eliciting a few spoken words from children who have never ever spoken anything. In our case, our child has spoken before (in sentences) and has never lost his understanding of language...so I think that with the CORRECT therapy...we can hear him speak again.