… if he is alone

… if he is certain that his conversation will not disturb or annoy others

… if he is a doctor, receiving a call from his answering service or from his office

… if he is a father, expecting a report from his children or from their babysitter

… if he is at a raucous event such as a football game, where his shouting will only add to the general uproar

… if it is truly necessary for him to bring another person into the conversation at a business meeting, at that very moment

… if he truly believes there is a chance that an emergency is in the offing.

…when he is behind the wheel of a vehicle, of any type

… in church or during a theatre performance, a movie, or at a concert

… at a table in a restaurant of any type – be it fast-food or first-class

… in the waiting room, or in the examining room, at a doctor’s office

… when standing in line at the grocery store, the post office, a deli, or any other place where customers may find themselves trapped as helpless witnesses to his conversation

… in an elevator, unless he is alone, or in the company of only friends or co-workers

… in the workout room at his gym

… on the “quiet car” of a train

… in the cabin of an airplane, unless some actual, dire emergency demands it