You Need Geniuses at MIT, Harvard, and Columbia To Make an Animal-Shaped Xylophone

By Andrew Liszewski on at

The same research and technological innovations that a team from MIT, Harvard, and Columbia University used to create a pitch-perfect xylophone with bars shaped like animals could one day help make your electronics quieter.

You might be asking yourself why Fisher-Price hasn’t created a fun animal-shaped xylophone already. Turns out, it’s not as easy as it sounds. Idiophones, musical instruments like xylophones and violins that produce sound by vibrating the instrument itself, require careful craftsmanship to get the tones and resonant frequencies just right. That’s why an exquisite sounding violin can be so expensive.

If you were to just cut a chunk of steel into the shape of a lion, for example, and hit it with a hammer, it would probably sound pretty awful. To overcome that, the team of researchers, led by Columbia Engineering’s Changxi Zheng, combined established techniques in acoustic modelling, computer graphics, old-school mechanical engineering, and modern 3D printing to develop software that would automatically warp and deform a given shape—like a lion—so that the final product would produce a specific desired tone.

The resulting shapes don’t always resemble their original design, though. For instance, after being manipulated to properly produce the ‘E’ note, the third bar in that animated GIF up top looks nothing like the cartoon elephant it started life as. Where as the fifth bar still resembles a lion. But the software strives to find a good balance between maintaining the bar’s original shape, and ensuring it produces the required tone.

So what does this mean for anyone outside the research world, besides a xylophone toy made of various Star Wars shapes that’s probably already in production? The software developed here could also be used to fine tune the shapes of blades on a computer fan, making future laptops run even quieter. Or be used to refine the shapes of moving parts in a car, to help dampen resonant frequencies and sounds inside the cabin.

It could even be applied to architectural design, for designing bridges or other structures that don’t amplify vibrations and increase stresses like the infamous Tacoma Narrows Bridge over Puget Sound that eventually shook itself to pieces.

[MIT CSAIL]