A voice user interface (VUI) allows people to use voice input to control computers and devices. In short, it's what enables voice experiences like the Star Trek computer and Alexa, Amazon's voice service and the brain behind millions of devices including the Amazon Echo.
VUI makes human interaction with computers possible through a voice/speech platform in order to initiate an automated service or process.
A VUI is the interface to any speech application. Controlling a machine by simply talking to it was science fiction only a short time ago. Until recently, this area was considered to be artificial intelligence. However, with advances in technology, VUIs have become more commonplace, and people are taking advantage of the value that these hands-free, eyes-free interfaces provided in many situations.
However, VUIs are not without their challenges. People have very little patience for a "machine that doesn't understand". Therefore, there is little room for error: VUIs need to respond to input reliably, or they will be rejected and often ridiculed by their users. Designing a good VUI requires interdisciplinary talents of computer science, linguistics and human factors psychology – all of which are skills that are expensive and hard to come by. Even with advanced development tools, constructing an effective VUI requires an in-depth understanding of both the tasks to be performed, as well as the target audience that will use the final system. The closer the VUI matches the user's mental model of the task, the easier it will be to use with little or no training, resulting in both higher efficiency and higher user satisfaction.
USES
The explosion of VUI has come about at the same time as we’ve started to have more fluid cross-device experiences. Imagine you wake up in the morning and ask Alexa to play your favourite podcast on Spotify. You don’t finish it before leaving home, but as you start your commute, you open Spotify on your phone and you resume your podcast at the point where you paused. A small convenience, sure. But restricting those barriers and adapting to the user’s circumstance creates a very slick experience.
In July 2017, Google Assistant had 378 services, whereas Amazon Alexa had 15,069 skills. Alexa entered the market roughly two years before the Google Assistant so these numbers are understandable. Still, even the most obvious and straightforward services that you’d expect Google Assistant to have aren’t in production yet — for example, compatibility with GSuite. These will undoubtedly be available in the near future but currently the existing capabilities feel quite restricting.
VUI Applications and Devices;
Google Assistant
A virtual personal assistant developed by Google that is primarily available on mobile and smart home devices. Unlike Google Now, the Google Assistant can engage in two-way conversations.
SIRI
Siri is an intelligent personal assistant, part of Apple Inc.'s iOS, watchOS, macOS, and tvOS operating systems.
Amazon Echo
Echo is an Alexa-enabled speaker you control with your voice. Echo connects to the Alexa Voice Service to play music, provide information, news, sports scores, weather, and more--instantly. All you have to do is ask.