A group of 11 multimedia technology companies have endorsed an extension to Microsoft Corp’s DirectX 3.0 applications programming interface to enable hardware acceleration of 3D audio in PC games. Called 3Dxp, the extension lets software developers address a variety of competing three dimensional audio technologies with a single programming interface under Windows. The extension has been endorsed by Aureal Semiconductor, Creative Labs, Diamond Multimedia, DiamondWare, Gulbransen, Qsound Labs, Rockwell Semiconductor, S3 Inc, Spatializer Audio Labs, Texas Instruments and VLSI Technology. The largest obstacle developers faced in using 3D sound was picking between all the incompatible and competing technology suppliers, said Tom White of the Interactive Audio Special Interest Group, which released the specification. 3Dxp aims to level the playing field so software developers will jump in and start using 3D audio in games. The 3Dxp DirectSound 3.0 API Extension is an open, royalty-free specification developed by members of the 3D Audio Working Group of the Interactive Audio Special Interest Group, which is also developing recommendations for improving and evaluating current 3D audio offerings. 3Dxp consists of 14 commands that include the various kinds of data needed to project 3D audio images from a pair of speakers or conventional headphones. It includes additional commands to pass 3D audio parameters such as object position, volume, speed and orientation to dedicated audio processing chips and also prescribes a standard way of phrasing 3D audio data to enable it to be processed faster. The 3D Audio Working Group consists of 250 hardware and software developers as well as music composers and sound designers with a common interest in improving the sound quality for interactive media.