const directsound.DSBCAPS_STICKYFOCUS;

Changes the focus behavior of the sound buffer. This flag can be specified in an IDirectSound::CreateSoundBuffer call. With this flag set, an application using DirectSound can continue to play its sticky focus buffers if the user switches to another application not using DirectSound. In this situation, the application's normal buffers are muted, but the sticky focus buffers are still audible. This is useful for nongame applications, such as movie playback (DirectShow™), when the user wants to hear the soundtrack while typing in Microsoft Word or Microsoft® Excel, for example. However, if the user switches to another DirectSound application, all sound buffers, both normal and sticky focus, in the previous application are muted.