Voice technology has made great strides, contributed to improving societal conditions and changed lives of hundreds of millions of people during the course of its evolution over the last 40 years.  During the evolution of voice technology, even early on, the need to interact with computers by voice required the launch of the conversational user interface.  As early as the late 80s, techniques were developed to allow a person to interact solely through voice with a computer in order to complete written reports or even allow a disabled person to control a robotic system to access items in his/her environment.  During the course of development, the user experience or conversational user interface has been central to the success or failure of numerous products. The user experience has evolved significantly and interacting with chatbots of today can be natural and even humorous, lending the chatbot a ‘human-like quality’. This keynote speech covers the evolution of the user experience of spoken voice technologies.  Major milestones of the voice user experience that have been achieved during the course of its evolution as well as the design and implementation criteria for those milestones will be discussed.  Exploration of new technologies, such as voice identification,  that can change the user experience will also be presented.