Voice interface is soon going to be a thing of the past. What with Hitachi Inc of Japan having developed a technology which can be used successfully for the pupose of interacting with Computer. It especially places the ability to physically challenged people to give commands and control the computer.
Previously there have been forays into the same area by US comapanies but it required a chip to be implanted inside the brain under the skull. But the news technology is a radical deviation from the previous research in which people only require to wear a head band with sensors weighing 1 Kg of wieght. Infrared rays are transmitted through the brain to map the blood movement and record activity of the brain. For example one person could use the Frontal Coprtex of ones brain which is used for problem solving and by doing some calculation there could make a train move or halt.
Cool but I say still crude. I think it should be able to read any text or graphical 2-d or 3-d image also from brain and directly input it into a editing software, then I think some progress would have been made. The presesnt system is just a crude achive ment of what would be possible in a year or two.