UI Design UX Design

Understanding Voice User Interface (VUI) System ?

VUI System

What is a voice user interface?

Voice user interface is the user interaction with the computer through a voice/sound platform which gives desired results. It is not just a means of contact with the customers, in fact, it involves a complete user experience where the interface understands and considers a user’s request, and initiates the process accordingly. The design process of a successful VUI involves the issue of emotion, whereby it studies the user’s voice and answers the query in the corresponding tone.

Let us explore the challenges faced by users in operating a VUI

  • People often find it difficult and cumbersome to use this interface
  • They do not like listening to automated marketing messages while using a VUI
  • Due to lack of knowledge or guidance, get lost in the menu or get stuck in the ‘loop’
  • Inability to understand the commands or the tone of the voice of the IVR system

The designers have to take the above-mentioned points into consideration while designing an efficient IVR. With the advancement of technology people will gain confidence in the IVR system and its use for mobile applications will become more prevalent.

Designing the VUI system

In a VUI, the voice is the keys means of giving the interface a ‘feel’. The designing process has to judge numerous criteria and go through many rounds of usability testing through the use of tools that you may find on this page overviewing 10 different webui test tool options, before coming up with the final product.

  • Testing- Testing of different voices is important with the users as they may have their set of comforts. A wrong voice will spoil the VUI and hence, it should be chosen carefully after a series of testing rounds.
  • Dialect selection- The voice can be decided as per the region in which the interface will be used. The locals of an area might be comfortable with a certain tone or the local language and hence, the choice of the voice should be based on these criteria. But sometimes a standard language is the best option as a regional language can pose understanding issues for those who are not familiar with that dialect.
  • Proper volume- The voice should not be too loud or too soft, the volume should be just perfectly pleasing to the ears as voice volume is directly proportional to speech persuasiveness.
  • Pace and pitch of speaking- Just like the volume, the pace of the voice should be correct. It should neither be too fast nor too slow and should be easily understandable to the user. A fast paced voice seems rude and harsh whereas a slow pace would seem lacking in confidence. The pitch of the voice should also be well regulated and be easy to understand.
  • The tone of the voice should be dependent on the script. For e.g. – A marketing voice should sound positive but the tone of a banking or billing service should be relatively neutral.
  • Voice personalisation- Some services give the user the option to choose a voice. It could be fun, convenient and more homely for users to be able to interact with their choice of voice.

By lending an ear to the clients and the users, and conducting a series of multiple tests with real time users, the task of accomplishing an error free and efficient VUI system can be successfully achieved.

  • The voice interface has to be designed keeping the target audience in mind. For the general public, the interface would have to be developed in a user-friendly manner, providing help and guidance through every step. But for a specialised group of experts, the help can be reduced and more concentration should be towards efficiency.

Key points for a successful VUI

Analysing the user’s voice and following commands requires sophistication of technology. As the technology will advance, it will not only recognise the voice of the user, but also the volume, tone, and pace. This would be a big breakthrough as it will go a long way in enhancing the Voice user experience.

Two keys factors in this respect are….

Authentication using ‘voice’

Complex and lengthy passwords and pin codes are usually required to be typed by users to validate authenticity. With the existence of VOI, the users will be at ease and can just speak a few words. The interface will determine the voice, pace, pitch and other vocal cord traits and establish authenticity by comparing them to their stored voice data.

Emotional response

A VUI is a complete interface that takes the emotional aspect of the users into account. It will analyse their emotional state, whether happy or mellow and then frame responses based on this study. This will make the user more comfortable with the interface and would turn to using it more often.

Future impact of the VUI technology

With the successful application of VUI, the use of cumbersome buttons, icons, will be a thing of the past. The laptops and computers will become sleek as they would not require a keypad or a typing device. To operate a keypad, the user has to stand in front of the computer/laptop. But we the use of a Voice Interface the user will be free to move around.

With the absence of keyboards and typing sections in computers and mobiles, the screens could be larger and full-screen view of the content. Laptops could be further simplified into tablet computers and the desktop computer would consist only of the screen and the CPU.

Every electronic gadget that requires a remote control like the television, air conditioner, microwave ovens, photocopiers and all other devices will not require the remote control operations as they would be operated with voice commands.

Though the VUI seems extremely promising, it requires hurdles to overcome…..

  • The VUI would have to have a certain level of expertise wherein it could distinguish between commands, tones, and voice, ignore background commands so that the correct input is laid and it can be processed properly to give the right response.
  • The VUI will have to be intelligently programmed to give output as per specifications. The user might require the output in point form or in a paragraph, the interface should be competent enough to filter information, through various levels if required, and then give the desired result.

Wrap Up

With new tools and technology been developed, it is not a distant dream to operate a fully functional and successfully running Voice User Interface. With advanced technologies and high-quality plug-ins, it is easy to develop a system, but the idea is to make it usable and develop a complete user experience. The user might not listen well, the developer might not consider environmental sounds while developing the software, and hence, the end result would be far from desirable. For e.g. – A voice interface in a bank will have a completely different environment than that of a locomotive conductor’s workplace. A hospital helpline will be a priority service and would require prompt feedback’s.

A great alternative would be to repeat the query or the question before churning out the results. Also, providing supporting options to the user might help him in recollecting facts he must have previously forgotten. Customization is extremely vital as specific problems require clear solutions. Creating a user-friendly Voice interface will help make the user’s experience a pleasant one, which will, in turn, be profitable for the developer.

About the author


Manoj is a designer/front-end developer with 8+ years of experience. Other than front-end coding, he loves to write on design trends.