Bohairic dialect in Bohairic pronounciation (B) was the one used by the Coptic Church all over Egypt, due to the availablity of its manuscript that were produced by monks of the desert of Shihat (Natron Valley), & the condition was so for many many centuries, & it's so until now, in a very few minority of churches in upper Egypt.
In the 1858-1860, there was a trial to merge the Coptic Church with the Greek Church so that one Patriarch be the head of both Churches in Egypt, but the trial did not succeed till now. The union of pronounciation of Coptic & Greek was one of the demanded requests as was witnessed.
The teacher of Coptic in the Patriarchal Church at that time was Arian effendi G. Moftah, he was very enthusiastic to the change of Coptic sounds, he made a project & applied it to do so.
1. He thought that as long as Coptic & Greek have almost the same alphabet so they share the same pronounciation, thus any change of Coptic pronounciation towards Greek is a reform. This was his hypothesis.
2. Also, the expected union between the 2 churches was a co-factor, to proceed.
3. The Egyptians were at that time suffering stresses, & inferiority complex, due to the appearance of the French expedition (1798-1801) & the scientists of the expedition who stayed many years after the expedition left Egypt. Many people turned out thinking that whatever European is correct, due to the vast difference that was between Egyptians & French people.
The fact is that many languages share same alphabet, e.g. Latin alphabet is used in English, French, Spanish, Italian, German etc. but the phonetic value of sounds vary much from one language to another, imagine pronouncing parlez vous francais in English pronounciation, or a name like Southampton, in a french style. That is the difference in addition, Coptic borrowed Greek letters in approximate values to what they had at that time, Greek language itself was changed much overtime. Bohairic pronounciation (B) is a natural one, while the GB came as a synthetic man made one.
The pronounciation of Arian effendi G. Moftah was spread by the central power of the Klirikia (Theological Seminary), Patriarchal School and it took about 50 years to be generalized all over Egypt & used till now by almost all Churches except for a very few minority in upper Egypt that refuses any priest from outside their village.
Along course of spread, the Old Bohairic (B) pronounciation was mistakenly named by Arian's scholars as Sahidic, or that the change would help an expected merge. It was generalized after that.
The Old Bohairic pronounciationIt has got no strict rules of pronounciation, it is as variable as English, sounds much like a natural language, where you can not state what are the rules of pronounciation. It just comes by listening & practice. It fits 100% with slang Egyptian tongue. Many consonants are the same as the Ecclesiastical pronounciation e.g. z,k,l,m,n,r,s,sh,f,kh, others are different. Here's a rough guide about its pronounciation.
* Alpha (a, a) as in far & at
* Wida (b,w) as in bad, was
* Gamma (g,n,gh) ...
* Dalda (d) as in duck
* Eia (a) as in at
* So (6)
* Zada (z)
* Hada(h) (a, ee) as in at, teen
* Tita (t) as in town
* I (i) as in pin
* Kappa (K)
* Laula (L)
* Mei (M)
* Nei(N)
* Eksi (X)
* O (o,oa) as in off, oat
* Bei (b) as in boat
* Ro (R)
* Sima (S)
* Dau (D,T) as in do, wet
* ha ( i, w) as in pin, how
* Fi (F,B) as in fat, bat
* Kei (K,sh, kh)
* Epsi (ps)
* Omega (oa) as in boat
* shy (sh)
* fy (f)
* khy (kh)
* hoary (h, h) as hat & occasionally, like haa (7a) in Arabic as in temsa7, 7arb,
* djandja (dj) as in age
* gshima (gsh, sh)
* di (di) as in dig
from
http://www.geocities.com/remenkimi/pronounciation.html