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The PrepareEvent() method dynamically loads the media only when it is absolutely required. With this method, the Action Event metadata must be in a SoundBank and the associated media files must be accessible in the file system. The corresponding structure metadata can be included in the same SoundBank as the Events or in a separate SoundBank. When using this method, the SoundBank that contains the Action Event metadata is loaded and kept in memory using LoadBank(). Prior to Action Events being called by the game, they are “prepared” by the sound engine. Preparing an Event will load all referenced media files from the file system, and also load all referenced structure metadata from a SoundBank, if it is not already loaded. When the Action Event is no longer required, it can be “unprepared” and the corresponding media files are purged from memory. To keep memory usage at a minimum and to avoid any duplication of media files in memory, Wwise performs a check before loading any media file to ensure that it is not already in memory.

	Note
	Only Action Events can be prepared in advance. The “PrepareEvent()” method does not work with Dialogue Events.

The following illustration shows how Events can be prepared in advance so that only required media files are loaded into memory.

When the metadata (also referred to as structures) is not stored in the same SoundBank as the Events, Wwise needs a way to find the corresponding data that resides in another SoundBank. To do this, Wwise includes references to the corresponding content stored in other SoundBanks. Wwise can use either names or IDs to refer to other SoundBanks. To use the SoundBank name in the sound engine, you must select the Use SoundBank Names option on the SoundBanks tab of the Project Settings dialog box. To use IDs, deselect that option. For more information, refer to SoundBanks Tab.

Media that is referenced by a SoundBank must be stored as loose files on disk or, otherwise, be resolvable by the low level IO (such as in a File Package).

This method is generally very efficient in terms of memory usage, but it does require additional disk seeking, which may not be appropriate in situations where many files are already being streamed from the disk. Also, in cases where the game uses States and Switches, media files could be loaded into memory unnecessarily. For example, if you have different crowd sounds for the different moods or energy levels of the crowd within your game, you wouldn't want to load all of them into memory if only the angry Switch sounds are valid within a particular zone of the game. To overcome this problem, you can also “prepare” specific States and/or Switches that load only those media files that are associated with the prepared States or Switches.

The following illustration shows how Switches can be prepared in advance to further limit the amount of media that is loaded into memory at any particular point in the game.

Although preparing Game Syncs in advance can optimize memory usage, be aware that it also reduces the speed at which media is loaded into memory. Longer read times result from the sound engine needing to seek through the disk to find the sounds that correspond to the prepared game syncs.

By dynamically loading only those audio files that are required, this second method gives you greater flexibility to handle situations where you have either very large zones or levels with many sounds or very limited amounts of memory available to store both Event data, structure data, and media.

As you can see, each method has their own strengths and weaknesses. The method you choose will depend on the specific scenarios, requirements, and limitations of your game. After deciding on a strategy, whether it be a single method or a combination of several methods, you can begin to populate and fine-tune your SoundBanks accordingly.

	Note
	The LoadBank, AkBankContent_All, PrepareEvent, PrepareGameSyncs, and AkBankContent_StructureOnly functions are accessible through the Wwise API. For more information on loading SoundBanks and preparing Events and/or game syncs, refer to the Integrating Banks section of the Wwise SDK.

For a detailed overview of the different methods you can use to manage your SoundBanks, refer to Strategies for Managing SoundBanks.