November 5, 2012
Virtual Sound Ball Could Be Next Big Thing For Home Theaters
[ Watch the Video: Virtual Sound Ball, Home Theater´s Next Big Thing ]
Lee Rannals for redOrbit.com — Your Universe OnlineDon't have room for those wall-mount speakers to create that theater feel for movies? No problem, new audio technology could help you build your own home theater using a "Virtual Sound Ball."
The new audio rendering technology produces a sound field "more clearly and accurately" to an original sound source by establishing an array system of loudspeakers and a software interface.
The team succeeded in building an audio rendering system that will considerably improve the current 3D audio effects technology.
You can create 3D audio effects by stereo speakers, surround-sound speakers, speak-arrays, or headphones. This effect gives the listener an illusion that sounds are being produced in the 3D space around them.
The effects are the result of manipulating the listener's sound perception through the placement of virtual sound sources in the 3D space to alter the way the sound is played.
In a 3D audio and acoustic environment, listeners can recognize the location, distance, and direction of sound sources including behind, above, or below the listeners.
During the latest project, a team of researchers completed a set of simple integral equations to create a virtual sound source inside of an area enclosed with loudspeakers.
The placement of a virtual sound source within the array of loudspeakers and the reproductive of sound field from them are considered "physically unlikely." This is because the sound field reproduced form the internal virtual source should satisfy an homogenous wave equation.
The team's proposed theoretical basis for the solution is based on the integral equations. They developed a loudspeaker array system that is composed of a large number of loudspeakers, ranging from 24, 34, 50 and up to 64 speakers to create a virtual sound source they call the "Virtual Sound Ball."
"We used many loudspeakers in order to build multipole virtual sound sources that would give a listener more freedom to move around without losing an auditory illusion of target sound fields perceived by the listener," Professor Yang-Hann Kim from the Department of Mechanical Engineering (KAIST), said in a press release.
He said their method offers a very high quality 3D sound, as well as an individualized, customized optimal sound that can be controlled and adjusted based on the needs of each listener.
When the listener hears a classical music concert from an audio set, the sound field produced from the Virtual Sound Ball makes the listener feel like sitting in an actual concert hall.
The researchers established a controllable sound field within a restricted area based on the loudspeaker setup, and formed multipole sound balls by focusing and localizing acoustical energy both in space and time.
The sound balls can be moved around as needed by a listener and controlled through a software interface.
The researchers developed a "spatial equalizer" that allows a smartphone or tablet to control the sound field reproduced from the sound ball just the way a balance knob in a stereo audio system works.
"We expect that this technology, which is ready for an immediate translation into commercial products, will upgrade our home and personal audio system to the level of professional settings," Professor Jung-Woo Choi, who also worked on the project, said in the release.