 As in addition to "hello", "halloo", "hallo", "hollo", "hullo" and (rarely) "hillo" also exist as variants or related words, the word can be spelt using any of all five vowels.The use of "hello" as a telephone greeting has been credited to Thomas Edison; according to one source, he expressed his surprise with a misheard "Hullo".Alexander Graham Bell initially used "Ahoy" (as used on ships) as a telephone greeting.