Illustration by Freddierick Mesias

As product and UX designers, we’re entering uncharted territory when it comes to some of the newer and more groundbreaking technological developments. From chatbots to augmented reality to other emerging technologies, we can look at these developments and shy away, or we can embrace the challenge of harnessing them in the best possible way.

Nowhere is this more evident (and trickier) than with voice user interfaces (VUIs). These new “assistants” and other tools and applications are becoming more commonplace every year. And like venture capitalist Benedict Evans said, “If you think voice UIs are the future, verbally describe, aloud, everything you see and touch on your phone today.” That’s what is expected of these interfaces, and the gap between a weird, modulated voice and the dulcet tones of an Alexa (or Siri or Cortana) as a true assistant gets smaller every day.

All said, it’s not as complicated as you may think. By keeping a few key design concepts in mind while designing for a VUI, you’ll be able to make something that’s useful, delightful, accessible, and even profitable.

Waveforms and sounds can look many different ways, but they all sound the same.
Waveforms and sounds can look many different ways, but they all sound the same. Image credit Adobe Stock.

Why you should be designing for VUIs

If you’ve been paying attention to the most popular and widespread types of technology, you’ll have noticed that most of the bigger tech companies (like Apple, Microsoft, Facebook, and Amazon) are all designing their own voice assistants. As people spend more of their waking hours in front of screens, they are likewise moving away from those screens when possible. A quick look at data provided by Comscore shows us that many homes with smart speakers (and their included voice assistants) rely on those assistants for tasks that may have formerly only been a Google search away—think setting alarms, getting the weather report, and asking general questions.

Smart speaker ownerstend to use their speaker for simple tasks like setting timers or answering general questions.
Smart speaker ownerstend to use their speaker for simple tasks like setting timers or answering general questions. Image credit Comscore.

As these assistants become more common in homes, offices, and vehicles (not to mention our mobile devices), designers with an understanding of the specific needs inherent to voice user interface design are going to be in high demand.

Best practices for designing VUIs

If you’re interested in learning about how to design voice interface software, below are some key practices and considerations to think about as you get more involved with this particular field.

Keep it simple

To begin with, don’t design your interface to be more complicated than necessary. When you’re creating voice interface software, there’s value in minimizing the steps or prompts between the initial query (“Hey Siri…”) and the answer your user seeks. Basically, keep it simple.

Because the user can’t visually see the path and the pattern (like in a graphical user interface), where to start and where to go next should be as plain as possible. We talk to people all day, and it’s easy to get frustrated when you can’t clearly get your point across. While we can’t (or shouldn’t) get frustrated enough to give up and “just Google it” when talking to a friend or relative, that hurdle is much lower when it comes to VUIs. Minimize the opportunity for frustration and keep your voice user interface simple.

Anything that we as designers add to the process or interface that doesn’t add to or facilitate progress toward the user’s goal is extra. While it’s important to structure potential interactions in ways that allow for easy discoverability, it’s just as important to heed Einstein’s clever paraphrase of Occam’s Razor principle: make your VUI as simple as possible, but no simpler.

Keep it natural

Speaking of frustration, it’s easy to take our interaction patterns, especially our spoken patterns, for granted. Yes, the user is talking to a computer, but it doesn’t have to be weird. Keep the interactions natural.

How you structure your call-and-response interactions and the suitable replies and responses can and should vary depending on the type of task your user wants to complete. If you’re designing for a finance or property management scenario, for example, your design should probably be relatively formal and brief. On the other hand, a less serious approach might be more suitable and comfortable when doing something more casual like ordering a pizza or answering a phone call. Think about how a person might speak in a particular situation and try to maintain a similar tone.

Design your VUI as though you were conversing with a friend.
Design your VUI as though you were conversing with a friend. Image credit Adobe Stock.

Keep it together

The pace and progress of user-facing technology seems to accelerate every year. Computers can do many amazing things, but they do have limitations. Keep this in mind and use those constraints to your advantage. Design for a VUI that keeps its possibilities together.

Placing constraints on user behavior instead of giving your user limitless options may seem counterintuitive at first. If the technology behind the voice can do these amazing things, why not remove the reins and let it run free?

The truth is that by limiting the actions users can complete with your VUI, you as a designer can focus on perfecting and honing the limited options you make available. Having a solid grasp on the limitations within your VUI and the underlying tech will help you guide your users and reduce errors, creating a more delightful and productive user experience. Just like how natural language can help keep users headed toward their goals with minimal distractions, purposeful limitations can keep those same users within the boundaries of their own expectations.

Keep it goal-oriented

Finally, so much of user-centered design can and should focus on the needs of the user first (or at the center). Just like a web search or a call to a restaurant for takeout, VUI designers should always try to keep the interactions brief and goal oriented.

To do this, focus on the general design practices of incorporating research-backed personas and user flows. Whether it’s a VUI, a GUI, or a landing page for a product, users typically engage in order to solve a problem or accomplish a specific goal. Just like keeping it simple and keeping it together, stay focused on what will help your users accomplish their goal. This will be the best use of your time and resources.

Keep your users’ eyes (and voice) on the prize.
Keep your users’ eyes (and voice) on the prize. Image credit Adobe Stock.

Enjoy the VUI

Whether it’s for a website, a SaaS product, or a voice user interface, the best advice for designing remains the same. If you keep it simple, focused, and natural, your user will be able to accomplish their goal and maybe even have a good time along the way.