Keyword Manager is the key for Voice Command when we are using HoloToolkit. Keyword Manager allows us to specify keywords and register the methods to be executed for specific keywords in the Unity Inspector. We don't need to write explicit code for this.

From Assets|HoloToolkit | Input | Scripts | Voice, include the Keyword Manager as a component for the Root object.

The Keyword Manager also includes a setting to either automatically start the keywords recognizer or allow your code to start it. In our case, we will start it automatically by setting up the Recognizer Start option as Auto Start in the Inspector window.

Keyword Manager uses a set of keywords to match with and performs actions corresponding to each keyword.