It has become a common development strategy for many games to plan for content that will become available after a game has been released. Often, this strategy is included in the schedule for creating a game and, if properly planned for, can be a seamless experience for adding additional content.
One key aspect of developing content to be distributed after release is: All DLC content must be created using the same Wwise Project that was used for the main release. Also, to ensure compatibility, the same Wwise version must be used for the Main and DLC releases. A basic scenario for managing DLC can be found in the Wwise Help and also includes considerations and limitations involved with preparing your project.
It is important to devote time to understand the process involved with preparing for the eventuality of downloadable content. With the right approach, the ability to modify implementation and include additional audio can enable new creative potential after the initial release.
For more information on Downloadable Content: