Wwise SDK 2018.1.11

Used when hardware-preferred frame size and user-preferred frame size (AkInitSettings.uNumSamplesPerFrame) are not compatible.

If true (default) the sound engine will initialize to a multiple of the HW setting, close to the user setting. If false, the user setting is used as is, regardless of the HW preference (might incur a performance hit).

AkAndroidSoundEngine.h の 61 行目に定義があります。