Most of my business is done using phone. When I say business, it is not the multi-billion dollar empire but the coordinating the activities of different teams located in different geographic locations separated by national boundaries and time zones. This will not amount to billions of dollars. May be a million dollars. On second thoughts, a fraction of million dollars. On further thinking, who knows?
It is a common practice to mute the phone when someone thinks they have nothing to contribute. It often happens to me. I'm on a call with somebody who is supposed to do an activity based on my instruction. We are to analyze the results together. The people at the other end mutes the phone because the last task communicated would take a couple of minutes. They have good intentions. They don't intend to distract me with the background noise. While doing so, they don't realize an important aspect while putting the phone call on mute. They are distancing me away from their activities.
The background chatter provides a connection for me. I know they are working and also having fun instead of doing tasks monotonously. At times, I know they are cracking jokes while working. They are other people pestering them for output while they are working towards what I asked for. The stray conversations in the background also let me know if they understood the task assigned to them. It also lets me know if they are on the right track.
How do I know all this if you mute the phone? By muting the phone, while on a important call during work, adds to the mental disconnect with your coworker at the other end!