Wwise SDK 2018.1.11

SHAPE pool size. When 0 (default), the sound engine estimates the required pool size according to the maximum number of XMA voices (uMaxXMAVoices) below, assuming that sounds are stereo. Note that multichannel sounds take more memory than what this heuristic predicts, especially when they are streamed.

AkXboxOneSoundEngine.h の 65 行目に定義があります。