Voice is quickly becoming a prominent way of how we interact with our digital world. During the 2016 Google I/O Keynote, Google CEO Sundar Pichai announced that 20% of all queries on its mobile app and Android devices were made using voice. This shouldn't come as a surprise; advances in speech recognition and understanding coupled with the convenience of voice, makes it an efficient and natural way of interacting with our devices, if used properly.

HoloLens provides a natural fit for voice due to its lack of peripheral devices and contextually situated placement. In this section, we will explore how we can make use of it; we will start by looking at how to use keywords to control the robot (independent phrases that encapsulate a specific task), and then explore how we can allow for more complex forms of voice input, such as dialog and conversational interactions.