Now, giant ball speakers for 3D surround sound

Researchers are developing a new 3D super-surround-sound system by experimenting with a giant sphere that has 40 loudspeakers on its surface.
Commercial surround sound systems pan audio back and forth between speakers, but physically reconstructing a sound field could produce an experience much more similar to what you hear in the real world.

By knowing how different sound fields interfere within the space, researchers can choose the position of a virtual source and sculpt the resulting soundscape by controlling the signal sent to each speaker, the 'New Scientist' reported. "This type of system can be considered to be analogous to a video hologram. If we can reproduce all the sound that goes through the surface of the sphere we can accurately reproduce what's inside," says Fazi.

The team recently synthesised a concert inside the sphere. Different instruments were first recorded on separate tracks, like in a studio recording, then virtually repositioned in the space at different elevations, angles and distances from the centre.

During a demo, people listened to the virtual concert as well as to the musicians playing live and could hardly tell the difference. "We achieved a high degree of realism," says Fazi. Now the challenge is to scale the system down so it can be used in cinemas, at home and in small devices. Devices like cellphones are too small to accommodate many speakers, so the researchers are looking at how perceptual tricks could reduce complexity while retaining the same sound quality.