Wwise SDK 2015.1.9

Handle to the window associated to the audio. Each game must specify the HWND that will be passed to DirectSound initialization. The value returned by GetDefaultPlatformInitSettings is the foreground HWND at the moment of the initialization of the sound engine and may not be the correct one for your game. It is required that each game provides the correct HWND to be used.

AkWinSoundEngine.h の 58 行で定義されています。