After calling the DirectSoundCreate function to create a DirectSound object and investigating the capabilities of the sound device, your application can create and enumerate the sound buffers that contain audio data. The IDirectSound::CreateSoundBuffer method creates a sound buffer. The IDirectSound::DuplicateSoundBuffer method creates a second sound buffer using the same physical buffer memory as the first. If you duplicate a sound buffer, you can play both buffers independently without wasting buffer memory.
Your application must use the IDirectSound::SetCooperativeLevel method to set its cooperative level for a sound device before playing any sound buffers. Most applications use a standard priority level, DSSCL_NORMAL, which ensures they will not conflict with other applications.