Software Says This Call Is Too Important For Push To Talk

Here's an odd one. The researchers at PARC have been developing a system that monitors how engaged people are in a push-to-talk conversation and automatically determines if the call should be shifted to a regular phone call. The idea is that PTT calls are shorter and more informal -- but it's a pain once involved to shift it to an actual phone call, since it involves disconnecting and one side calling the other. Still, is there really a demand for this? It seems like it would be even more distracting to have a PTT call suddenly switch to a regular phone call.