"h......is for"

I'm following along again with Toni's "a....is for" meme.
Feel free to join in anytime, Toni won't mind at all.

This week's letter is H.
h.....is for hello.

The following passage has been taken from the book I'm currently reading.
"Gone Tomorrow" - a Jack Reacher story by Lee Child.

It could be fact, it could be fiction, I have* no way of knowing.
But I liked it, so here* it is.


"One of the dog walkers came close enough to speak. The dog was an elderly grey mutt and the walker was an elderly white woman of about eighty. Her hair* was done and she was fully made up. She was wearing an old-fashioned summer dress that really needed long white gloves to be complete. The dog paused and looked at me mournfully and the woman took that to be a sufficient social introduction.
She said "Good evening".
It was close to three o'clock and therefore morning, but I didn't want to appear quarrelsome.
So I just said "hello".
She said, "did you know that word is a recent invention?"
I said "what word?"
"Hello", she said. "It was developed as a greeting only after the invention of the telephone. People felt they needed something to say when they picked up the receiver. It was a corruption of the old word Halloo. Which was really an expression of temporary shock or surprise. You would come upon something unexpected, and you would go Halloo! Perhaps people were startled by the shrillness of the telephone bell".
"Yes", I said, "perhaps they were".
"Do you have a telephone?"
"I've used them", I said. "Certainly I've heard* them ring".
"Do you find the sound to be disturbing?"
"I always assumed that was the point".
"Well, goodbye", the woman said, "it has* been most pleasant chatting with you".
Only in New York, I thought......

So what do you think?
Fact?
Fiction?
Is hello a relatively new word and not as old as the rest of human* speech?

* = more "h" words.