There is actually a history behind the word "hello" and why we use it whenever we answer a phone call. According to the Oxford English Dictionary, the use of word "hello" was first published in 1827. And, during those times it was not even considered as a greeting. But, according to the author Ammon Shea who wrote the book "Reading the Oxford English Dictionary" said that, in 1830 people used the word "hello" to gain attention of people. Moreover, the OED says that, it was Thomas Alva Edison who highly recommended the word "hello" and to use it whenever we answered the call. Later on, Alexander Graham Bell said that, the better word for "hello" would be "ahoy". And, after when the telephone arrived the word "hello" became "hi".