Visualizing Sound Without A Computer

[Emre] sent in a cool art piece he’s been working on that visualizes your voice without the use of a microcontroller.

The project is called Visible Voice only consists of a laser, mirror, audio speaker and a phosphorescent disk. The laser shines onto a mirror mounted on the speaker and is reflected onto the disk. When an audio signal is played through the speaker, the light bounces off the mirror and produces a waveform on the disk. Think of it as the lowest tech way of building a model of a CRT; the laser is the electron gun and the speaker is a deflection coil.

Right now, [Emre]’s project displays a waveform along a circular path on the slowly rotating phosphorescent disk. Anyone wanting to copy this project could use a moving belt of the same material giving a much more linear (and straighter) waveform trace.

After the break you can see [Emre]’s friend [Ivan] testing out the glowing laser waveform visualizer.


22 thoughts on “Visualizing Sound Without A Computer

  1. Thats freaking awesome! I made something like this when I was younger. I basically glued some small mirrors to two speakers then pointed a laser that bounced off of both of them then played music through the speakers. It produced a cool effect where the laser moved with the music, often making perfect circles when there was constant bass.

  2. It appears to have a very non-linear frequency response (bass looks like it shows up much better (unless my headphones have such poor bass that I am mistaken)). That would be a real asset if this were on display in a kids museum or something because it would reward non-shrill sounds among those playing with it.

    1. Veeery nice project!

      The frequency response is defined by the speaker, i guess (which is non-linear) . And for mechanical resons (mounting a mirror on top) its probably a fairly large broadband speaker which has probably a main-range of about 200Hz – 2kHz. The amplitude is significantly lower in higher ranges because of the inertia of the membrane.

      1. addition: actually the used speaker, visible on the project site is a subwoofer (larger than i thought) probably mainly acting around something like 30- 800 Hz….

      2. @none & @spike

        Hey guys, thank you for your interest. I actually used an 18″ speaker at the beginning and made a mechanism to rotate the mirror (the picture you saw on the making of link). But this setup did not work, specially when a child or girl speaking. The reason was the speaker was only responding to low frequencies.

        Later I replaced the 18″ speaker with a 6″ one and really glued a tiny mirror where the angular motion is maximum. And this solved the problem.


  3. “Simply, a laser beam is reflected through a mirror glued on a speaker.”

    what an understatement, look at the picture of the speaker and its obvious a lot of work went into setting it up. The pic is too dark to tell how its setup; I suspect the mirror is hinged, and the speaker adjusts the angle.

  4. Well done! It reminds me of the old “silly string” audio visualizer in some ways :) This is a wonderfully simple solution to what can often be overthought. Great job builder! I did Dino’s from HaW and this one is on the table for today :) Keep up the good work :)

  5. Very inventive… nice one! I did a similar thing recently that drew a waveform… it took a lot of time to set it up just right. Your method is elegant! Well done.

  6. Very cool, it sort of gets the concept of a record player across. I suspect the phosphorescent material would not survive the bending of a belt, but a large diameter drum could work (like really old phonograph cylinders).

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