Discussion Forum—A Way with Words, a fun radio show and podcast about language

The discussion on the silent 'n' in "kiln" reminds me of another surprising factoid I picked up some years ago.   NPR used to play a BBC game show called My Word, a sort of contest between four professional wordsmiths.   The moderator would pose questions and the contestants would try to remember or in some cases work out the answers; the questions were sometimes on definitions or pronunciations, but other times one was called upon to name the author of a little-known bit of poetry or figure out the common element in a list of words.   In the latter category, once there were put forward four words: I don't remember them all now, but one was "orange" and I'm pretty sure another was "asp".

The answer delighted me:   Originally, the word was "a norange", and somehow the 'n' moved and it began to be spelled "an orange".   The same for "an asp".   In the other two words the 'n' went the other way; there was originally "an object" and by some transmutation it became "a nobject".

With "orange" you can see the history because in Spanish the word is still naranja.   (Actually, I think Spanish got it originally from Arabic.)

Extra-credit question: What is the name of the process by which the 'n' moves between the noun and the article?

No, really, what is it?   They said, on the program, but I don't remember.