Introducing Coral Prime, our robot mascot. Art by Aileen Gozali.

R2-D2. WALL-E. Doraemon. These are just a few of the beloved pop culture robots that have been with us from childhood to adulthood. However, our affection for them doesn’t come from the fact that they are robots. We feel connected to them because they’re actually human.

The number one goal of a movie is to tell a story. Often times that’s difficult to do with a character that moves mechanically or can’t really talk. To make these metal creatures have dynamic roles and strong relationships with people, movie creators turn to the art of sound design.

If you think about it, sound is a vital part of our life experiences. They help elevate our mood, tell a story, or remind us of certain things (think Monday Night Football, a text message, or the school bell). Sound acts as a type of emotional and sensory memory that provides vivid sensations much like eating food or watching a Harry Potter movie. Even if you can’t hear, the pulse and beats of sound can be felt through your body. Music is sound on overdrive.

Sound designers are conscious of this. When they work with directors to turn otherwise monotonic robots into interesting characters, they use an arsenal of sound cues to convey certain experiences, moods, feelings, and states of mind. The goal of a sound designer is to make the robot talk like a person, but not actually use words. They have to perform what the robot wants to say though tones, timbre, and pitch.

Combined with the help of human puppeteers, sound designers bring these movie robots to life. But can we do this with consumer robotics? Can we do this with vacuum robots for instance?

When we designed the Coral One, sound design was something very important to us. We all have deep connections with movie robots, and we wanted that same interaction and relationship for people with their Coral One. To do this, we made a constraint: no tech sounds.

What do we mean by tech sounds? That “beep boop” sound, the 8-bit KITT-Knight-Rider sound. It’s cold and electronic. It doesn’t really express, and its message is very linear. One boop is on. Beep boop is off. Etc.

So where do we start? Well, we looked at a lot of music that was composed during the time of these movie robots. From Whitney Houston to Kanye we noticed that almost everyone used some kind of analog keyboard, like a Wurlitzer or Fender Rhodes. Just to give you a feel, this is what that instrument sounds like:

From there, we decided to use a Nord Piano. It’s handmade by these Swedish audiophiles engineers who have recreated history’s greatest pianos into one console. We dialed in a tone we liked that paid homage to the old keyboards but had a modern flare to it.

The actual Nord Piano we used to record all of the sounds for the Coral One.

After establishing our instrument of choice, we looked at scales on the piano. Different keys or scales often reflect certain moods. Many composers use C Major for happy, E Major for lovey-dovey stuff, D minor for demonic, and so on.

We decided to use Bb Major and F Major. The reason? Bb major is very aspirational and space like. Star Wars, Star Trek, and E.T. all use Bb Major as a main key. F major is very calm and hopeful. Almost all Pixar soundtracks use F major in some major way.

By combining these two elements, the Nord Piano and the Bb/F Major keys, we were able to come up with a sound design that reinforces the Coral One as your cleaning sidekick. What do you think?