How it became universal?

Everytime you pick a phone you say ‘Hello’.

From where does this ‘hello’ came from.

We all know that telephone is Alexander Graham Bell’s child. But the greeting ‘Hello’ was coined by Thomas Edison.

Alexander Graham Bell first used the word ‘Ahoy’ as telephone greeting. Bell for his entire life, preferred to answer the phone with “Ahoy.” But, Thomas Edison once misheard the word to Hullo. This became universal with time and finally we ended up using the word for our day-to-day conversation.
The word ‘Hello’ has a short ‘e’, which keeps the mouth more closed than ‘o’ or ‘a’, and ‘-lo’ makes a quieter ending. This is very important for a telephonic conversation, as on phone, we address unseen and unknown person.

‘Hello’ has an older history. The word is approx. 200 years old. It was used in publications as early as 1833. These include an American book called The Sketches and Eccentricities of Col. David Crockett, of West Tennessee, which was reprinted that same year in The London Literary Gazette. The word was extensively used in literature by the 1860s.