kind of a minor linguistic rant

To all the linguists among you (and other like-minded people):

Although I am certainly no expert in any of this, it is my belief that the words sin and sing are pronounced completely differently, and that regardless of the final sound in either word, they would not be considered minimal pairs. Well, sin and sing are two different words with two different meanings, and the final sound of one word differentiates it (in meaning, not only in pronunciation) from the other, and so they would be except that the ending sounds aren't the only ones that are different.

That's pretty basic level linguistics, but I was in my Hispanic Linguistics class this morning and the professor and I disagreed over this word. I asked if the final sounds--[n] and [ŋ]--were even relevant in determining whether or not it was a minimal pair since all the other sounds weren't the same. In order for two words to be a minimal pair, all the sounds have to be the same except for the one that differentiates the meaning. For example, hat and cat would be a minimal pair because the sound [k] in cat makes the word mean something totally separate from hat. Technically there's a little breath of air (an aspiration) that is pronounced following the c, but if the word is pronounced without the aspiration, it's still understood to mean cat, so they're allophones, and psychologically, the difference in pronunciation doesn't matter (except that you might recognize it as non-native).

So that said, besides the final [n] and [ŋ] all other sounds in sin and sing are not equal. The first sound in each word--[s]--is the same. And now I'm at a computer that won't let me type the symbol for the sounds (plural) that the i makes in these words, so I'll do the best I can. The i in sin is pronounced the same way the i in pin is pronounced. The i in sing is pronounced more like the word seem, (although not exactly, I think) and is much farther back in the mouth. Now my professor insists that the vowel in these words are pronounced exactly the same, but I disagree. Sin and singe have the same i sound, but I think that sing and singe do not rhyme.

Again, maybe this is dialectal. My professor, who isn't from the south, says his dialect of English is the standard one (he's from southern California)--I do know that my accent isn't, but anyone who isn't from the southern United States (whether you consider your pronunciation standard or otherwise), how do you pronounce those two words? Are the vowels different or the same? Does the i in sing sound like the one in singe or more like the sound in seem?

Thoughts?

[Note: I'd have the <> around each i but it's messing up the html. Everything's becoming italicized! I can't stop it!]