Each version of this integration matches a specific build of Unreal Engine 4. Here is what has changed in the 2016.1.1 release of the integration (in addition to upgrading to the new Unreal build).

Migrating to the UE4.11/4.12 Wwise 2016.1.1 integration

Unreal Engine 4.11/4.12 - Wwise 2016.1.1

• WG-29972 Fixed: Multiple potential threading issues with the auto-destroy behavior of the AkComponent.
• WG-29979 Fixed: EndOfEvent callbacks are now always called.
• WG-30004 Fixed: SetGameObjectOutputBusVolume is now exposed in Blueprints and AkAudioDevice.
• WG-30404 Fixed: The attenuation scaling factor now properly works on AkComponents.
• WG-30409 Fixed: It is now possible to decode Vorbis-encoded files.