Origins of English Double-C Pronunciations

Looking into Pronunciation of double consonants, turned up an apparent rule for pronouncing a double-C in English that seems to parallel the Italian rule for pronouncing a single C. If the "cc" is followed by a bright vowel ("i" or "e"), it is pronounced /ks/:

accent, occipital, eccentric

Otherwise it is pronounced /k/:

account, occasion, occupy

A dictionary search throws up a few exceptions to this, which mostly appear to be musical loan words from Italian which are still pronounced as the in original ("acciaccatura" for example).

The question is this: how did this rule come about? The parallel with Italian is close enough to make me very suspicious, but I haven't been able to prove a connection between the two.

Forgetting about the "doubling" of the consonant for a second, in English, some consonants, most notably c and g, but also s, t, x, and the pairs ch and th are softened when followed by softening vowels (usually i and e are the softening vowels, but a and io soften t, s, and a softens x for example).

Most of the "softenings" originated in Late Latin as a result of either intervocalic voicing or palatalization before front vowels.

• Emerson, Ralph H. (1997), "English Spelling and Its Relation to Sound"
• Or, if you want a more accessible resource, the Wikipedia article isn't bad.

Now what does it have to do with a double c?

Let's look at an example: eccentric

The first c is followed by a consonant, c, so it is pronounced as a k, while the second c is followed by an e, so it is pronounced as an s. Putting those together gives a ks sound.

On the other hand, in a word like occasion, the second c is followed by an a, which doesn't soften the c. So both cs are pronounced as k's, which is in turn pronounced as a single k sound.