Outside of the manual generation of SoundBanks, another method that is becoming common is the use of the SoundBanks Definition File as a way to automatically generate SoundBanks based on level, character, object, material or any information from the game. A definition file can be generated automatically by external applications, such as a game level editor, or manually by creating a tab delimited text file that lists all the events in your game, classified by SoundBank. When SoundBanks are generated, Wwise packages all the Actor-Mixers, Containers, Sounds, and so on that are used by the events contained within each SoundBank. If some of the Sounds in a SoundBank are Sound Voices, then a different version of the SoundBank is generated for each language supported by the Wwise project.
For more information on SoundBanks: