Each version of this integration matches a specific build of Unreal Engine 4. Here is what has changed in the 2016.1.5 release of the integration (in addition to upgrading to the new Unreal build).

Unreal Engine 4.11/4.12/4.13/4.14 - Wwise 2016.1.5

• WG-31588 Fixed: Make sure no sound is played on a dying actor.
• WG-31860 Fixed: Remove warnings found by clang static code analysis.
• WG-31876 Fixed: Allow relative paths for the Wwise install path.