States are a great way to alter the properties of sounds to reflect the changes that are occurring in game. For example, you can modify the properties of your sounds by creating a "Stun" state when a grenade goes off nearby, or a "Teleport" state when a character is teleporting from one location to another. In Wwise, each Wwise object or bus can only subscribe to one state. But what if you need two or more states to be applied to the same Wwise object.
Scenario
Let's say that all the 3D sounds in your game pass through a single bus called "3D Sounds". In your game, the 3D sounds can be affected by the Stun state and the Teleport state. To achieve this in Wwise, you can apply the Stun state to the 3D Sounds bus and then create a parent bus that subscribes to the Teleport state. The following illustration demonstrates a possible sound structure:
This type of sound structure setup gives you the flexibility to have your sounds affected by the Stun state, the Teleport state, or both states simultaneously.
