evidence: Similar to Graham Bell’s reason for liking "ahoy hoy", Edison liked "hello" as a telephone greeting because it was easily heard and distinguished from other words, even over long distance transmissions (for the time). As Edison stated, "hello" could be heard clearly on a transmission "ten to twenty feet away". Edison originally tested this using a prototype of Graham Bell’s telephone system. The word "hello" also has somewhat obscure origins, though many etymologists think it came from the English "hullo" or "hallo", which derive from "hollo", which was an exclamation to draw attention to something. This word, in turn, is thought to derive from "holla", which meant "stop or cease". Another slightly less popular theory is that "hello" ultimately derives from the Old English "hál béo þu", meaning "Hale be thou", which was more or less just a way to wish someone good health. [...] - Because "hello" quickly usurped "ahoy hoy", by 1889, telephone operators became known as "hello-girls".