Wwise SDK 2018.1.11

Default is 1 audio quantum, also known as an audio frame. Its size is equal to AkInitSettings::uNumSamplesPerFrame / AkPlatformInitSettings::uSampleRate. For many platforms the default values - which can be overridden - are respectively 1,024 samples and 48 kHz. This gives a default 21.3 ms for an audio quantum, which is adequate if you have a RAM-based streaming device that completes transfers within 20 ms. With 1 look-ahead quantum, voices spawned by continuous containers are more likely to be ready when they are required to play, thereby improving the overall precision of sound scheduling. If your device completes transfers in 30 ms instead, you might consider increasing this value to 2 because it will grant new voices 2 audio quanta (~43 ms) to fetch data.

Number of quanta ahead when continuous containers should instantiate a new voice before which next sounds should start playing. This look-ahead time allows I/O to occur, and is especially useful to reduce the latency of continuous containers with trigger rate or sample-accurate transitions.

AkSoundEngine.h の 197 行目に定義があります。