"Ultra-thin" diffuser gives clarity to sound

The new design (pictured above right) from North Carolina State University (NC State) and Nanjing University is said to use less material, which would reduce cost and take up less space.

In a typical room with flat walls, sound waves usually bounce off the walls, which creates echoes and overlapping sound waves that result in uneven sound quality.

"Sound diffusers are panels placed on the walls and ceiling of a room to scatter sound waves in many different directions, eliminating echoes and undesirable sound reflections - ultimately improving the quality of the sound," said Yun Jing, an assistant professor of mechanical and aerospace engineering at NC State and corresponding author of a paper on the work.

Schroeder diffusers are already widely used but can be bulky because the size of a diffuser is governed by the wavelength of the sound it needs to diffuse. Specifically, the depth of a Schroeder diffuser is about half of the wavelength of the lowest sound it needs to diffuse.