I notice no or almost no difference between the pronunciation of these words.
Are they really pronounced the same way?
I personally prefer to pronounce "accept" with a very distinctive "a", like the "a" of "America". Do you think it is a problem?
At least in theory the <a> in “accept” is pronounced as the unaccented schwa /c/ (a central vowel) while the first <e> in “except” is pronounced as the short /w/ (a mid high front vowel).
I have an Oxford dictionary with very useful pronunciation symbols (IPA) written behind the words. I looked up both words and this is what this dictionary tells me:
Note that even the stress on the syllables are exactly the same. The only difference is that accept starts with a schwa, and that except starts with a /ɪ/ like in <sit>. So there is a difference, but indeed quite hard to tell when the language is spoken in its normal speed.
PS: The symbols are written in recieved pronunciation accent.