The last but hardly the least important form of input for the HoloLens is Voice. The Voice component is designed to let the user look at a hologram, see any commands associated with that hologram, and simply say the command out loud to invoke it.

A convention has been laid out for developers. See it, say it means that if you have a voice command for the user input, a label with the appropriate button should be visible; for instance, a button that causes robots to destroy a village in a game might say destroy. When the user Gazes at the village and utters the word, he can smile as the army of robots descend on those poor villagers. Oh, the humanity!

Now, apart from voice commands, the Voice system can also be used for taking dictation, as well as communication. Dictation works surprisingly well inside Unity apps, and in the chat room social media-driven world we live in, real-time voice communication is essential.

It should be noted that only one of these modes can be running at a given...