Sound-speed visualiser

This project is an experiment to make the speed of sound visible: roughly 20 handcrafted modules—each equipped simply with a microphone and an LED that flashes the moment it hears a sound—lined up at one-meter intervals.

A Wave of Light Across the Dark

Lined up in a row across a park at night, a single sharp handclap at one end sends a ripple of light racing into the distance like falling dominoes. If someone claps at the far end, you can watch the wave of sound and light surging straight toward you.

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Each standalone unit is a straightforward build consisting of a tiny microcontroller, a high-sensitivity microphone, an ultra-bright LED, and a battery.

Arranging them across a flat surface indoors lets you see sound ripple outward in concentric circles. I'd love to try this across an entire gymnasium floor someday.

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Watching an invisible physical phenomenon reveal itself as a tangible trail of light was far more mesmerizing than anticipated. Following the buzz on Twitter, I received numerous inquiries from science educators and museums wanting to borrow the setup (though the timing overlapped with my relocation to Sydney, so it didn't materialize). Still, it proved to be an experiment with tremendous potential as an educational showcase.