John, that link leading to John Ellis' post about RACHAP spells it out well. I ended up getting my devices at Bethesda and spent about $700 for them, less than 10% of normal retail. They are hi tech and can be controlled by my iphone through bluetooth. If you have tinnitus you can also download an app that can inject certain sounds to help counter the ringing. Great program and I hope they continue it. Good luck!