CalifJim“However, some people still cling to an older style in which words like historic (first syllable not stressed) take an.”
I'm one of those "clingers". (A Klingon?)

But it's not actually something I do consciously. That's just the way I've always spoken. For a long time I didn't even realize I did it. An ESL student of mine once asked me why I'd just said "an historical event", and that's when I first realized that I actually used "an" with those sorts of H-words.
I say "a history book", but "an historical novel".
It's only a very slight N, but there's an N sound there nonetheless.