Each version of this integration matches a specific build of Unreal Engine 4. Here is what has changed between the 2016.2.5.6121.484 and the 2016.2.6.6153.513 release of the integration (in addition to upgrading to the new Unreal build).

Unreal Engine 4.15/4.16/4.17/4.18 - Wwise 2016.2.6.6153.513

• Added support for Unreal 4.18
• WG-33970 Fixed: Crash on Mac when running game with PAK files.
• WG-34907 Fixed: Performance improvement in FAkAudioDevice::Get().