What is Voice UI (VUI) and how to design it effectively?
13May 2021

What is Voice UI (VUI) and how to design it effectively?

What is Voice User Interface?

Voice interface design (VUI) is a tool that uses speech recognition technology to allow the users to engage with an application or electronic devices using voice commands. The voice interface technology equals GUI in most cases, providing users with a smooth experience. VUI finds applications in tasks like searches, adjusting controls, post updates, and getting directions. VUI and GUI can be interchangeably used in the same system for convenient handling of tasks. A report says that in 2019, 59% of online searches came through voice searches. The VUI market sector is predicted to reach $24.9 billion by 2025.

Why is VUI important for brands?

Speaking is an inevitable human behaviour. Voice is the most powerful and straightforward method for communication. How efficient would it be if an electronic device can respond to the users' voice?

  • Voice input is the only means of conveying emotions and intentions that other interfaces like GUI cannot perform, making VUI the essence of Artificial Intelligence (AI).
  • VUI can be used as an additional facility that users can exploit as per the requirement and are not bound by the 'just typing' feature.
  • VUI is of utmost importance to visually impaired and physically challenged people to work, thus getting equal rights for employment in computer-based jobs.
  • VUI is a perfect tool for any tasks that benefit from hands-free use, like cooking or driving applications, smart home devices, and applications with an emotional component, like physical exercise or productivity.
  • Voice interfaces are very effective at eliminating bestrew sites and thus allowing the users to bypass complicated navigation systems.
  • It is incredibly convenient to use a voice command to get a task done, for instance, setting a reminder alarm

Tips for designing VUIs effectively

It is mandatory to keep in mind the purpose, context, and applications of a VUI before designing it. Here are the steps to follow on designing a VUI:

1. Crowd-sourcing the requirements

In the process of designing a VUI, the first rule is to do user-centered design planning. The primary step is to gather information to understand the needs of the end-users, which will be the fundamental data for the product design.

  • Enquire and identify the pain points of the end-users and their experience and how beneficial it would be to incorporate VUI in their work.
  • Information on users' language, their way of speaking, and standard terms used in their work.

2. Defining the capabilities

The second stage of VUI designing is to form a framework of the device or application that is to be developed, which involves the following protocols:

Creating fundamental scenarios of interaction that are to be identified by the VUI application and prioritizing them based on the extent of usage in a work environment.

  • The compatibility of the identified scenarios with the voice input has to be tested.
  • The interface must realize the intent, utterance, and slot of the command. The UI and UX designers of a VUI must consider these variations when developing a VUI software.

3. Having a clear view of dialogue flow

It is essential to work out the challenges in creating a voice interaction between a user and the technology. The developers must form a prototype on how the dialogue flow would be on addressing a specific issue. The prototype must contain:

  • The main keywords of interaction.
  • The possible branching of the further conversation.
  • Example dialogues for the user and technology.

On creating the dialogue flow, the following points must be followed:

  • The number of steps to get the solution must be minimum
  • The process must be precise, not lengthy.
  • The flow of conversation must be natural without preaching to the user on what to ask.
  • The responses must be brief.

The VUI supplication must be sensitive to:

  • Identifying errors in a conversation
  • Spotting the ambiguous words and analyze what they could mean
  • Correct the misspellings and mispronunciations.
  • Avoiding irrelevant answers for questions that are not understood

4. Testing before implementing

When the VUI application is in the pre-final stage of delivery, it is crucial to test the quality of the product. Here are the factors to be tested to prove that the technology has reached the benchmark of the client company:

  • The VUI developers can create a target audience and execute the testing sessions to observe the users' interactions with the technology.
  • The developers can get feedback from the users to evaluate customer satisfaction.
  • The developers can also use simulators for testing the product design to know its efficiency.

5. Analyze and upgrade

Once the VUI product has hit the market, the developers need to observe the efficiency of its performance. The different aspects of the interface can be researched and upgraded periodically to fix the recurring issues. This action will let the users know that their voices are being heard.


A user interface is a crucial part that should be as simple and efficient as possible. Designing a user interface needs critical and logical thinking to plan the work that can ease specific tasks of the user. VUI is an indispensable tool that enables a more natural way of communicating with technology. Leveraging VUI will be a boon for any company to reduce physical contact tasks like typing and clicking with voice commands. VUI finds potential applications in AI-based devices that offer luxury at home and workplace.


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