Sound buffers have three processing modes: normal, head-relative, and disabled. Normal processing is the default mode. In the head-relative mode, sound parameters (position, velocity, and orientation) are relative to the listener's parameters; in this mode, the absolute parameters of the sound are updated automatically as the listener's parameters change. In the 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. This method sets the operation mode based on the flag the application sets for the first parameter, dwMode.