Each version of this integration matches a specific build of Unreal Engine 4. Here is what has changed in the 2015.1.7 release of the integration (in addition to upgrading to the new Unreal build).

Unreal Engine 4.12 - Wwise 2015.1.7

• WG-29917 Fixed: Fixed a case where the attenuation radius of AkAmbientSounds did not show up in the Editor window.
• WG-29991 Added AkEvent String Input Field to AkAmbientSound.
• WG-29997 Suppressed duplicate "LogAkAudio: StopAll API called" entries in the output log.
• WG-30000 Fixed: Changed meta properties of StartAllAmbientSounds and StopAllAmbientSounds.
• WG-30012 Fixed: Integrated GitHub pull request #5. Match the list of available platforms for SoundBank generation to the Supported Platforms under the Unreal project settings.
• WG-30014 Fixed: Fixed a crash when starting a Play in Editor session that uses a dedicated server.
• WG-30031 Fixed: Removed usage of the World global pointer.
• WG-30218 Fixed: Crash when connecting the Wwise Profiler to the Android platform.
• WG-30255 Fixed: UE4 crash when adding key to Ak Event Track in Matinee.