The Bell Labs stereo technology can be used in an Internet Protocol (IP) environment and incorporated into both teleconferencing and video conferencing systems. Stereo conferencing technology gives participants a better way to hear and comprehend multiple streams of conversation.

"With the rise of IP-based audio and videoconferencing, we are moving into a new age of multimedia communications that focuses on realism," says Fred Juang, head of Bell Labs acoustics and speech research department. "To deliver on the promise of virtual collaborations, we need to recreate lifelike audio and video renditions of a physical setting. Stereo sound gives us some of the natural audio cues we get from our ears in a live meeting about who is speaking."

In creating the first stereo-based conferencing technology, Bell Labs researchers needed to tackle the extremely complex problem of stereo acoustic echo cancellation. Without echo cancellation, users would hear feedback that occurs when a speaker and a microphone are too close.

Current echo cancellation relies on an audio technique that uses single channel cancellation, which identifies one acoustic path between the speaker and the microphone. In the stereo environment this technique does not work because the sound is carried in multiple acoustic paths between the speaker and the microphone.

To overcome this, Bell Labs audio researchers developed new algorithms that modified the stereo signals in a way that allows for the correct path identification without harming the stereo sound.

Bell Labs stereo conferencing technology is expected to be integrated into a number of Lucent teleconferencing and video conferencing products including Lucent Collaborative Video, an IP-based videoconferencing system that delivers high-quality video and audio to multiple parties in a PC-based solution. Lucent also plans to license the technology to other companies for use in their conferencing products.

Lucent Technologies, headquartered in Murray Hill, N.J., designs, builds, and delivers a wide range of public and private networks, communications systems and software, data networking systems, business telephone systems, and microelectronics components. Bell Labs is the research and development arm for the company. For more information on Bell Labs multimedia communications research visit http://www.multimedia.bell-labs.com or for more on Lucent Technologies, visit http://www.lucent.com.

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• Acoustics
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• Sound effect
• Acoustics
• Speed of sound
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• Ultrasound