GetMute
Status = m_PipeOutCtrl.GetMute( wPipe,
m_MonitorCtrl.GetMute(wBusIn,wBusOut,bMute);
ECHOSTATUS GetMute(WORD wBusIn, WORD wBusOut, BOOL &bMute);
ECHOSTATUS GetMute(WORD wPipeOut, WORD wBusOut, BOOL &bMute);