Matching Kinect Audio with Video

I have a project dealing with video conferencing using the Kinect (or, more likely, four of them). Right now, my company uses these stupidly expensive cameras for our VTC rooms. The hope is, using a couple Kinects linked together, we can reduce the costs. The plan is to have four/five of them covering a 180 degree arc so the Kinects can see the entire room/table (still a lot cheaper than our current cameras!). The applications would choose a video stream coming from a Kinect based on who at the table is talking. Plan is fine in theory, but I've run into a snag.

As far as I can tell, there is no way to tell which microphone array corresponds to Kinect Runtime object. I can get an object representing each Kinect using:

Device device = new Device();
Runtime[] kinects = new Runtime[device.Count];
for( int i = 0; i < kinects.Length; i ++ )
    kinects[i] = new Runtime(i);

And every microphone array using:

var source = new KinectAudioSource();
IEnumerable<AudioDeviceInfo> devices = source.FindCaptureDevices();
foreach( AudioDeviceInfo in device in devices)
{
    KinectAudioSource devSpecificSource = new KinectAudioSource();
    devSpecificSource.MicrophoneIndex = (short)device.DeviceIndex;
}

but I cannot find any way to know that Runtime A corresponds to KinectAudioSource B. This isn't a huge problem for the two Kinects I'm using (I'll just guess which is which, and switch them if they're wrong), but when we get up to four or five Kinects, I don't want to need to do any kind of calibration every time the application runs. I've considered assuming that the Runtime and KinectAudioSource objects will be in the same order (Runtime index 0 corresponds to the first AudioDeviceInfo in devices), but that seems risky.

So, the question: is there any way to match a Runtime object with its KinectAudioSource? If not, is it guaranteed that they will be in the correct order so I can match Ru