I picked that example on purpose, as I couldn't think of a silent leading consonant (a word where it starts with a consonant but sounds like a vowel) other than that.
We -do- go by the sound rule--if it sounds like a vowel, it's "an", if it sounds like a consonant, it's "a". That was my point :)
Of course, I didn't mean to "sound" like I was disagreeing with you. I was meaning that your point about the sound rule was the correct one for our phonetic language, as opposed to some rule about what the word looks like.
(So, my question's answer would be, I suppose, European should have an "a" as an article, rather than an "an" because, although it begins with a vowel, it sounds like the "y" consonant.)