This message is passed to the PDD_WaveProc function to instruct the audio PDD to put the audio circuitry in standby mode.
This message should turn off as much of the audio circuit as possible. When this message is called again, the audio circuitry should be turned on as quickly as possibly. This message is sent between playback of sounds in order to minimize audio circuit power drain.
This message is declared in the Waveddsi.h header file.