I spent six years working with secondary-aged (14-21 years old) students with autism. It was one of the hardest and most rewarding things I've ever had the privilege to do.
At that time, the state of technology for these types of uses was woefully behind where it is today. Granted, we're talking about 1999-2005, but stay with me. The technology that non-verbal students used to communicate, for instance, was a huge, heavy piece of metal and plastic that had barely programmable capabilities for certain words and phrases that would be spoken upon selection through a garish sound system rivaled only by 1980s clock radio speakers. This equipment was exorbitantly priced, and very inflexible. The one thing it did well (arguably) was stand up to some abuse. They were like small tanks. But the kids would have to wear them around their necks and shoulders, which could be extremely uncomfortable. If they didn't have it with them, communication with others became difficult.