I've noticed that same voice at a few airports as well. If it's the same one I have in mind, it's used at my home airport, DAY.
It wouldn't be related to any FAA or TSA requirements - it's simply a convenience feature for passengers. The most likely reason is that they all happened to have purchased the clock system from the same vendor...or that multiple such vendors happened to use the same voice recording in their product. I'd guess the former.