Origin of the word "Hello"?

Hallo/hello is a variant of the earlier 'holla' and related to words like 'halloo' and 'holler' - a shout intended to attract someone's attention. (I suppose it could also be related to 'hail' and 'hey'.)
It is true that Alexander Graham Bell favoured 'Ahoy-hoy' for answering the telephone, but Eddison preferred 'Hallo' and Eddison won.
Alexander's fiancée, later his wife, was called Mabel Hubbard. If he had used her surname we would all have been greeted each other with the word 'Hubbard!'

They had that on my android smartphone 📱 and it said another person wanted to change it to ahoy