Be vewy, vewy quiet

I have been trying to recuperate from a bad congestion/fever episode from last week, and still can't talk because of all the coughing that has just worn out my throat. But I have noticed that many of the people that have talked to me over the past few days start whispering, too, when they are talking to me. They start out speaking in their normal voice, but gradually get softer and softer. It's like I'm conducting an unofficial science experiment: documenting cases of sympathetic whispering. I have actually asked a few people, "So, I know why I'm whispering, but why are *you* whispering now?" Inevitably, the person doesn't even realize that they have started whispering; they just automatically start to match my tone of voice. My dad told me once that, when he was in teh Navy and sometimes had to do stints as MP during tours of duty, he would be told to whisper to drink people in order to calm them down because they would automatically and unconsciously match the tone of voice of whoever they were talking to. I guess the technique works for anybody. And there's your weird science fact of the day!