I want to make the computer which will perform tasks by human's voice input.
for example ,just telling My computer to open instead of using keyboard or mouse.
can anyone help me?
What you are speaking about is called speach recognetion .
Just search on net for speach recognetion.
If you need to do it your self there's an algorithm calle "Hidden markove chain"
There's many ready programs for speach recognetion.
I think there's one called "Dragon"
What you need to know is using neural networks and learning algorithm for them such as 'back propagation' if you want to write a program to perform that!
ya alzomor is quite right the most famous software and i must say that the most effective speech recognition software is the dragon software
still you can find a lot of variety at www.soft32.com