Oh, I also wanted to add that when LoadModule() is called, I see the following in the debug output:
'UE4Editor.exe' (Win32): Loaded 'M:\Dave\GitHub\UnrealEngine-4.11\Engine\Binaries\ThirdParty\Oculus\Audio\Win64\ovraudio64.dll'. Cannot find or open the PDB file.
So it does appear that the DLL is loading.