Whisper, and I'll whisper back

I got to know this piece of human knowledge first-hand when I lost my voice for almost a week last November:

If you whisper to someone - it doesn't matter what you are saying - the person you are whispering to will probably whisper back in response. And they may not even ask why y'all are whispering.. at least not at first.

True? As I said, I've got a handful of empirical - and personal - evidence that says so. But you may want to do your own testing. At the least, it's an excuse to get close-close to someone.. in the name of science.

So, if anyone can confirm or deny my observation with their own experiences, let me know!