Is there a fourth way to get the audio device (IMMDevice)

Question

From the documentation of windows, I know that there are three ways to get the audio device:

IMMDeviceCollection::Item
IMMDeviceEnumerator::GetDefaultAudioEndpoint
IMMDeviceEnumerator::GetDevice

then I hook the three ways, And I see all of them has been called,
And I find a device been created but not by the above ways.
So how did it created with? (it is a default device)