Connecting Through Sound

These are the fundamental questions we set out to answer when our team of experts—sound, voice, visual, and interaction designers—started creating the Alexa experience. We knew that far-field devices presented new opportunities for sound design. But the challenges were complex. With a phone or laptop, you can mute it or turn it away from others to be polite. But we share the same air—Alexa’s interactions would be heard by anyone in earshot.

We wanted Alexa to be welcome in the home. If people wanted to mute her, that would mean we failed as designers. So, everything from alarm volume to boot-up sound had to be designed carefully with the customer in mind, considering how they would use the service. Sounds had to be noticeable but not annoying. Appropriately disruptive—alarms still need to be heard—but considerate to everyone.

The first step was research. What role does sound play in our lives? What other device sounds are out there? The answers would guide our efforts.

One thing you learn fast when designing sounds is that you’re triggering people emotionally. We’re hardwired to respond to auditory cues. Unexpected sounds cause a fight-or-flight response. A subtle “Uh-huh” in a conversation tells us the other person’s listening. When we hear a sound we consider irritating, we automatically have a negative feeling.

And when it came to devices, we were fighting decades of unpleasant sounds. From microwaves to fire alarms to car horns, device sounds usually have one purpose: to disrupt the environment. In a shared space, that simply wouldn’t do.

When you’re creating a new product category, incubation is critical. We took the time to experiment, try out different tones and textures, refine our sounds, and get feedback from a beta population.

One thing stood out: the sounds users responded to were unlike any other device sounds. They were calmer. Slower. Less percussive. People could process and interpret the sounds without triggering a fight-or-flight response. A little softness to the sound helped people connect to it.

This insight helped us design the Echo device’s boot-up sound. We realized early on that going from dead silence to suddenly hearing a voice felt too abrupt. So we built the Echo boot-up sound to start slower and lower, then repeat itself a little higher and faster as a melody, until Alexa speaks. That repetition was key—the human mind is built to identify patterns, to find predictability comforting. We used that understanding to craft a sound that served as a soothing, pleasant, warm buildup.

Let’s listen as Principal Sound Designer Chris Seifert puts this together for us...

Once we started pairing sounds with Alexa’s voice, we realized she wasn’t giving the non-verbal cues that keep conversations flowing. We knew a sound would help, but the challenge was more complicated than it seemed.

Some people like to speak their request uninterrupted, while others want acknowledgement that Alexa is listening. To accommodate both we found a middle ground—a low-mid frequency tone inspired by the phrase “Uh-huh”—that wouldn’t disrupt the speaker but would let you know Alexa is listening.

Again, let’s hear from Chris...

From the very beginning, the team included a cross section of disciplines: voice, sound, visual, and interaction designers. We crafted the experience by working closely every day to inspire the outcome. For example, after hearing how gentle and welcoming the boot-up sound was, the visual designers created “Alexa Blue,” a hue that complemented the sound and made Alexa feel like a welcoming presence.

We hit this magical point with our leadership where it no longer mattered what our individual disciplines were—we were just trying to make the experience great. Sound designers would step up and say, “I think we need voice here.” Or the voice team would say, “Hey, what if we replaced voice responses with a sound?”

That’s how we landed on “brief mode,” in which Alexa replaces “OK!” when appropriate with a confirmation chime—another piece of non-verbal communication to bring the experience together.

New product categories aren’t easy to create. And they fail more often than they succeed. The fact that Alexa took off like it did, as a first-of-its-kind sound/voice experience, is a direct reflection of the design process that created it. Taking the time to really dig in and explore. Collaborating with different teams. Refining ideas until you know they’re both useful and delightful.