Mention the term "voice control" and one of two scenarios usually comes to mind. The first scenario is of stilted, error-prone interactions, often involving the user repeating himself as the computer dumbly responds with "I don't understand." Worse, it can lead to the user shouting, "No!" as the phone asks if he would like to call the ex-girlfriend he hasn't gotten around to deleting from his contacts yet. This would be the "real world" scenario. The second scenario that may come to mind is of magical understanding, where the computer has all the language comprehension of a fluent speaker. It readily parses natural language and produces instantaneous results to any query or command. This is the "Star Trek" scenario.
"Computer, calculate warp trajectory."
"Did you say, 'Call Charlotte Padalecki?'"
There's a pretty wide gap between the two scenarios, and there has been a tremendous amount of time and money invested in pursuing the second scenario. The idea of controlling a computer with voice commands is an enticing one, to the point that it is in fact often referenced as an archetype of "futuristic" interaction. This is for good reason: it's not going to happen anytime soon.
