IMMDeviceEnumeratorVtable.UnregisterEndpointNotificationCallback

Undocumented in source but is binding to Windows. You might be able to learn more by searching the web for its name.
struct IMMDeviceEnumeratorVtable
extern (Windows) @nogc nothrow
HRESULT function(This_, IMMNotificationClient* pClient) UnregisterEndpointNotificationCallback;

Meta