I've been at this since the late 70's and still being worked on today. Most of the time the voice commands you give the computer via software that's running still has some issues with voice commands. Like in new vehicles today you would say call Pauline, but the computer would Say Play radio. This is where it gets confused.
Best way I can see after all these years with Voice is that even if you speak slowly the system suppose to understand voice. Same with the smartphone voice commands. Software today still not there yet. But better than the late 70's software.
I have voice command video on this issue on youtube clearly shows how certain voice commands confuse the software so it does something different.
Windows version it's okay your using it right now right. There is online versions you can test out but they suffer from the same issue. My Android Smartphone and now Windows 8.1 Smartphone both have this feature and it not 100% correct but not as bad as my SUV voice command.
I tell the female computer play track AUX (ipod) Promo Dance she comes back to say radio off. Or I tell her what time is it? She turns on the radio. I say she's 90% get's the voice commands right. In my other SUV it had auto climate control with voice. That was really something to deal with. Navi part is really something too but again improvements will make these devices work correctly.
Software mention here not 100% but you'll just have to work with it. The computer voice system base on how children are taught to learn to speak and understand. Same process. But the computer still needs teaching to understand you and what you want it to do.
