I really wouldn't worry too much about this. There has been a tendency to write and speak of "an hotel" but if you think of all the nouns which start with an aspirate (sounded) h, do you prefix them all with "an"? No! They sound ridiculous. However, where the h is silent, as in "honour" and "hour" the article "an" is correct.
The same situation occurs when you think of a word such as "unique". Nobody would write "an unique offer" just as they wouldn't write about "an unicorn".
- For Teachers