The word "hello" was invented because no one knew how to start a telephone call
"Over at the laboratories of Edison's rival, Bell was insisting on "Ahoy!" as the correct way to answer the telephone. It was trounced by "hello," which became the standard as the first telephone exchanges, equipped by Edison, were set up across the United States and operating manuals adopted the word."
http://www.buzzfeed.com/daves4/20-things-you-never-knew-about-popular-inventions