DOCOMO Develops Spatial Audio Transmission Technology for Mobile Phones


TOKYO, JAPAN, May 11, 2009 --- NTT DOCOMO, INC. announced today that it has developed a highly efficient mobile spatial audio transmission technology that enables a mobile phone user to assign a spatial position to each sound source when listening to multiple sound sources, such as during a game or a conference call.

The technology enables a user listening with headphones to, for example, hear each speaker's voice as if it were coming from a unique direction, creating a virtual face-to-face communication environment.

DOCOMO, which is continuing to research and develop the technology for eventual commercialization, foresees applications including mobile conference calls, tele-education and online games.

While existing spatial audio transmission technologies independently process audio encoding/decoding and spatial audio synthesis, the new technology offers a more efficient method by integrating the two processes, thereby minimizing bitrate (or bandwidth) and computation loads suitable for mobile phones and other resource-limited devices.

The processes are collaboratively performed on both the server and client sides. The server identifies the important sound components of each speaker's voice, compresses them efficiently into a single stream and transmits it to the mobile phones. Each phone then decodes the received stream and simultaneously synthesizes spatial audio images (see attachment).

DOCOMO will demonstrate its new spatial audio transmission technology using docomo PRO series™ HT-01A handsets during Wireless Technology Park 2009 at Pacifico Yokohama on May 12 and 13.

(Attachment) DOCOMO's Mobile Spatial Audio Transmission Technology

NTT DOCOMO is the world's leading mobile operator and provider of advanced mobile services. The company serves over 54 million customers in Japan, including 48 million using i-mode™, the world's most popular mobile e-mail/Internet platform, and 49 million using FOMA™, the world's original 3G mobile service based on W-CDMA. As a leader in the development of cutting-edge mobile technologies, DOCOMO is continually expanding the role of mobile phones as versatile and highly personalized "lifestyle tools" for everyday life, including with a wide range of innovative services for mobile payments, GPS, mobile TV, multimedia content and much more. NTT DOCOMO is listed on the Tokyo (9437), London (NDCM) and New York (DCM) stock exchanges. For more information, visit

docomo PRO Series, FOMA and i-mode are trademarks or registered trademarks of NTT DOCOMO, INC. in Japan and other countries.
FOMA service is only available in Japan.

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