INTRODUCTION

As their name indicates, voice user interfaces (VUIs) are interfaces that allow users to interact with computing systems through use of voice. Although our voice can be used in different ways, VUIs typically refer to communication through the use of language. This narrows down the problem at hand as communication through VUIs is a subset of communicating through aural user interfaces. It is possible to communicate with computers through sounds other than pronounced words and sentences. Different sounds can be used to communicate information through their frequency, amplitude, duration, and other properties that make them unique. However, language is how we naturally communicate, be it through voice or text; therefore, when referring to VUIs, we refer to communicating with machines through using pronounced language.

It is also true that most us have had very frustrating experiences trying to bypass the voice recognition system and reach an operator. However, this is not an indicator of the lack of value of voice recognition systems. In fact, most systems that lead users to be frustrated are those that have not been well designed or those that require a high degree of cognition by the computing system: something that computing systems do not do well yet. As we have already seen, the user interface problem is one of the biggest problems in mobile computing.