This is a copy and paste from the SoundStorm features from ASUS website. Hope this is something near what you are wanting to see.

An advanced architecture featuring, at a minimum, support for hardware acceleration of 256 2D voices and 64 3D voices, and advanced 3D positional audio.
Full support for all DirectX 8.0 features and capabilities.
The ability to incorporate support for Dolby Digital 5.1 and a Dolby Digital encoder in hardware to deliver an uncompromised, cinematic-quality audio experience.

With features such as the most advanced 3D positional audio, a real-time Dolby Digital encoder, and full support for DirectX 8.0 audio, the NVIDIA nForce APU exceeds the features and performance of today's top-of-the-line sound cards and other integrated sound solutions. When incorporated into a PC distributed processing design, such as the NVIDIA nForce platform processing architecture, or a game console such as Microsoft's Xbox, the end result is an uncompromised 3D audio experience.

Feature
NVIDIA nForce/nForce2 APU NVIDIA SoundStorm
DSP or HW-Accelerated 2D (Stereo) Voices 256 Voices
DSP or HW-Accelerated 3D Voices 64 3D Voices
DX8 HW-Submixer 32 HW-Submixers
DLS2 Acceleration
Per Voice Parametric EQ
Occlusion and Obstruction
Near Field Effects
EAX2 and I3DL2 Reverb
Global Effects (Reverb, Chorus, etc.)
Speakers 2, 4, or 6 Speakers
Microphone/Line Inputs
SPDIF Interface Yes
Software and Utilities Basic Enhanced
H/W Dolby Digital Encode