thy thigh [Germ x/c].

[petegray]

> [referring to [c,] and [x] in German]

>> 2. They have now come to contrast in initial position, at least before
>> /a/, albeit only in loan words, and only for certain speakers.

I had a thought about "durch".  Following the usual rule, it is pronounced
with /c,/, after a consonant.   But the actual pronunciation of the word is
often not with a consonantal /r/ but the back vowel replacement /upside down
a/.  This means we have a context in which a back vowel (or two, actually)
is followed by the front /c,/.   Of course there's an explanation for this
in the underlying pronunciation with /r/, but it still seems to show that
the difference between /x/ and /c,/ is not purely phonetically determined.

Compare the difference between clear and velarised /l/ in English - I cannot
think of any factors other than pure phonetics which determine the choice.

Peter