Sound buffers have three processing modes: normal, head-relative, and disabled.
In normal mode, the sound source is positioned and oriented absolutely in world space. This is the default mode.
In head-relative mode, the buffer is automatically repositioned in world space as the listener moves and turns. Values set and retrieved through methods such as IDirectSound3DBuffer::SetPosition, IDirectSound3DBuffer::SetVelocity, and IDirectSound3DBuffer::GetConeOrientation are all relative to the current position, velocity, and orientation of the listener.
In disabled mode, 3-D sound processing is disabled and the sound seems to originate from the center of the listener's head.
An application sets the mode for a 3-D sound buffer by using the IDirectSound3DBuffer::SetMode method.