See Sound with a CT Scanner

Continuing the inadvertent weekly theme of DIY projects for sound, PlasmatronX is here making a DIY CAT scanner, in order to visualise sound. The video details his meticulous process, starting off with the design stage, then onto scanning a furry toy cat in order to calibrate and verify the quality of the scanner, before going on to scanning sound, using a Raspberry Pi, amongst other things. All the details (and project files) are in the video description, with other similar videos on his channel with more below:

I built a DIY C.A.T. (Computerized Acoustical Tomography) scanner using Schlieren optics to map an invisible 40kHz acoustic levitation fields in 3D.

By taking thousands of 2D optical images of the sound waves and running them through a custom Python script using medical imaging algorithms, we can finally SEE the pressure nodes holding objects in mid-air.

Next time, we use this data to build and visualize directional speakers, volumetric displays and sound wave interactions /lens...
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What's in this video:
To make this work, I had to combine a traditional mirror-based Schlieren optical setup with a custom 3D-printed rotating platform. Triggering the camera with a Raspberry Pi introduced microsecond OS jitter which ruined the Filtered Back Projection (FBP) math. To fix the noisy data, I wrote a Python pipeline utilizing a Simultaneous Iterative Reconstructive Technique (SIRT) to clean the artifacts and export the arrays as DICOM medical files. The final 3D visualization was rendered in 3D Slicer (A super piece of free software)

Here are the timestamps..

0:00 - Can you CT Scan a Sound Wave?
0:30 - The Schlieren Optics Setup
1:01 - Building the C.A.T. Scanner
1:32 - The Cat Calibration (and Failure)
2:56 - The Math: Radon Transforms & Sinograms
4:10 - The Hardware Fail (Grinding a 3D Printed Bearing)
5:52 - The Timing Jitter Problem (Raspberry Pi)
6:13 - FLASH WARNING
6:20 - Warning ends/next topic
7:16 - The SIRT Algorithm Solution
7:45 - The Reveal: Sound in 4D
9:15 - What's Next: The Volumetric Display

More from PlasmatronX

• Madonna & Stuart Price on the Power Mac G5 04-Nov-26
• Lisa Maffia on So Solid Crew & Solo Fame 04-Nov-26
• Mix & Match Challenge: Episode 1 02-Nov-26
• Sprout Pi: A Modern Motherboard for iPods 02-Nov-26
• KARMA Turns M-VAVE FM-1Into A Groovebox 02-Nov-26