I’m a fan of Disney’s research labs. Meant largely to help Disney discover new ways to innovate in their parks and products, it’s a seemingly endless stream of crazy thinking.

Much of what they build and share is really, really cool, but hard to imagine being used by anyone outside of Disney. This crazy robot that draws massive pictures on the beach? It’s cool as heck, but unless you own a big stretch of beach to act as a canvas (as Disney does with its resorts), it’s not super practical.

Some things they come up with, though, are great because they’re just so different. So clever. Take, for example, this just released video on what Disney’s research hub is calling “Acoustruments.”

The video is a bit slow to start, so a primer: by manipulating soundwaves emitted by your smartphone’s speaker, they’re able to build buttons/knobs/sliders/etc. that can interact with your device without any power source or wired connection.

You launch an app that emits a tone through your phone’s speaker. When you push a button or twist a knob, the “acoustrument” modifies the tone much in the way your finger changes the tone of a flute when it blocks a hole. Push the button, the air pathway changes, the tone changes accordingly. Your phone’s microphone detects the tone change and reacts accordingly.

Why? Imagine an alarm clock that works with any phone, as long as it has a microphone/speaker on the bottom. Or, as demonstrated, a Google Cardboard-esque virtual reality headset with buttons that work with just about any phone, all without power/wires.

Like much of what comes out of Disney’s research labs, this was built in partnership with Carnegie Mellon.

Is it 100 percent practical in all cases? Is anyone going to throw out their soldering iron and go all-acoustic? Of course not. But it’s clever as all heck — and if you’re a builder/tinkerer, it’s definitely a trick to keep in your arsenal.