Wwise is an interactive audio solution that provides both an interface for audio design and a sound engine running alongside a game engine. When a Wwise project is complete, all necessary information is packed in a series of SoundBanks. A SoundBank is a package of Audio Sources, Events, audio structure information, prefetch data for streaming, and streaming references. For each added language or platform, you can generate a new set of SoundBanks specially designed for that platform. When the game is loaded, one or a series of SoundBanks is loaded by the game engine into the runtime memory (RAM) of the platform, ready to play audio. In Unity, Wwise will automatically select the correct SoundBank for your platform and declared language, as long as the SoundBank is selected in a Wwise Unity Integration Component, like AkBank.

In the above image, the Desert SoundBank will load on entering play mode. When a SoundBank is loaded into memory, the data size is directly proportional to how much it will take up in memory.