Principles of Voice Design
How designing for voice differs from designing for screens
Voice is the most natural way for humans to interact with each other. Humans have used voice and language to communicate with each other for over hundred thousand years. But how we communicate with our technology really hasn’t reflected that up until now. We’ve used a variety of interfaces in our personal computing – The 1980’s saw the popularity of home computing and graphical user interfaces, the 90’s saw the advent of the World Wide Web which opened up the possibilities of dynamic content within a browser, the 2000’s saw the era of the mobile phone. Just think of the interactions that you have on your smart phone today. You can tap, pinch and swipe your screen for different actions –interactions that didn’t exist earlier.
All these interfaces are screen-first experiences. But in the 2010s there was a paradigm shift to a new type of interface – voice user interfaces. Thanks to the advancements in Speech Recognition technology as well as improvements in cloud and data processing capabilities, computers can now recognize speech at a level similar to that of a human. Voice interfaces are slowly but surely gaining popularity with millions around the world using Amazon Alexa, Google Home and Apple Siri on a daily basis.
Designing for these voice interfaces is very different from designing for screens though. What makes voice design challenging is that there is no defined or ‘happy path’ to do something. Keeping that in mind, here are 4 principles of voice design:
1. Be Adaptable: On voice, a user can say the same thing in multiple ways. For instance, to find the weather on an app or website you would just enter the name of the city and click a couple of buttons to find the weather. On voice, here are few different ways a user can ask for the weather:
- “What’s the weather?”
- “Is it hot outside?”
- “Do I need an umbrella today?”
It’s upto the designer of the voice experience to adapt to what the user is trying to say. Users can also use synonyms for common words. As an example: While asking for t-shirt sizes, you ideally want your users to say one of three things – small, medium or large. But a user could choose to say tiny, mini or little to mean ‘small’. If your skill can adapt to the user’s conversation, you will know you built a good voice experience.
2. Be relatable: Ensure that you’re talking with your users and not at them. When asking for multiple pieces of information from your users, it’s better to elicit the pieces of information one at a time as opposed of asking your users to say it all at once. The former is a more conversational experience which reduces the cognitive load on your user.
3. Be contextual: In any conversational interface, context is everything. The human eye likes uniformity whereas the ear expects variety. Unlike an app or website, which strive to give you a uniform experience every time you visit, users of voice interfaces expect a lot of variety. Think of how you can leverage context to tailor your responses over time.
4. Be available: Rethink how your menus and top-level UI are structured. Flowcharts are typically used to define flows in any visual interface. For instance, to find the IFSC code of your bank account, you would have a flowchart that describes the decisions at every point starting from logging into your bank website. This representation doesn’t work for a voice interface though. A user wouldn’t ask Alexa to ‘open bank account, followed by account info and then IFSC code’. Thus, your menus should be structured with a wide top-level UI with different entry points, as opposed to a deep nested structure. That way a user could directly ask for their IFSC code.
These are 4 principles that encapsulate what goes into voice design. Conversational AI has opened up so many new avenues to interact with technology. With every new technology we have to be thoughtful about the design choices we make. With voice interfaces set to become our primary user interface, we have to pay special attention to our voice design to build experiences that customers will always return to.