@Steve_The_Cynic said in Case (in)?sensitive filesystems are :
Oh, yeah, I'm quite sure there is (or was historically) a difference in pronunciation.
My point was that what you call the same sound is actually several ones (although the distinction is quite subtle now and, as I said, most people don't make it anymore, or don't know that they make it...). So saying that there are several ways to write the "same" sound is a bit like a Japanese saying that the sound "ell" can be written "l" or "r" (yeah, I know, that's also a simplification...).
Anyway, I'm just being -ic, it's all details now...
Of course, my native-English ear can't hear that difference, but that's a whole different question.
I can imagine. I'm not a native-English speaker and when I stumbled one day on the radio on a comical show with different regional English accents, I was absolutely, totally, utterly lost. Even the few sentences that I could actually understand (OK, part of the comical effect was also using local slang, so probably no-one in the audience understood everything), I was entirely unable to say in which regard they were pronounced differently...
(1) Just like the "s" in "Étienne", except there it has disappeared in modern spelling as well as pronunciation.
I'm not sure in the case of "Étienne" (and it might be because it's the first letter of the word), but usually this evolution can be seen when there is a circumflex on the "e" (or other letter, btw). E.g. "tête" (head) was "teste", "maître" (master) was "maistre" etc. Although again, in modern spelling, the circumflex is disappearing, and even in pronunciation, it's less and less marked.
All that is overlaid with the regional variations and accents. Which in France is a somewhat loaded issue since there is a central office charged of defining what the "proper" french is, plus there was historically a strong central pressure to supress regional variations (as in, regional non-french dialects mostly, but also non-standard french pronunciations). So there are some people who react strongly on these issues. But it's a vanishingly small minority, though.