XPLMGetFMODStudio
XPLM_API FMOD_STUDIO_SYSTEM* XPLMGetFMODStudio(void);
Get a handle to the FMOD Studio, allowing you to load/process whatever else you need. This also gives access to the underlying system via FMOD::Studio::System::getCoreSystem() / FMOD_Studio_System_GetCoreSystem() . When a separate output device is being used for the radio, this will always return the FMOD::Studio that is running the environment output, as before. If you want to specifically target the headset output device, you can obtain that FMOD::Studio by getting one of the radio-specific output channelgroups and using the getSystem() call on that.