He or she is unconscious unable to communicate or react to surroundings or speech.

VOA: special.2009.08.11

The problem is as simple as the fact that millions of people who are unable to move or to communicate.

问题很简单,数以百万的人们无法行动，或者与人交流。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

At the hospital he fell into a coma and was unable to communicate.

VOA: special.2010.04.14