One thing I've noticed in my usual habit of listening to the world around me, is that humans generally say "Thank you!" in a conclusive tone. The pitch goes down as the words are spoken. It gives a sense of completion, conclusion. However, in the airport and flight announcements, there seems to be a pattern of pitch going up, making it sound like "Thank you?". I've always wondered if this is done on purpose and one of my theories is that making it sound a bit like a question keeps the audience alert, as if saying, "This is not it. There could be more information coming your way."

Have you noticed the same? Are you aware of the reason why? Let me know using the Contact Me form. I'm always eager to learn new things.