What does it sound like when you put someone on hold? Do you know? This is not a Zen koan. The answer is...of course not; you've never put yourself on hold.
Us, either. But consider the possibility that when you sneak off a conference call to answer another line, the entire team in Singapore or Cleveland or wherever is being treated to the un-dulcet tones of some Pandora channel or ads from the Egg Board (as we were abashed to learn just last month).