Accents on Letters Help?

I'm having trouble with a particular accent. It is the two adjacent dots over a vowel. I first read it in The Divine Comedy: Paradiso where the word "curs�d" appeared. I assumed the word was pronounced "cer SED" and the "e" is exaggerated, as this is the case with other words in middle english. However does this exaggeration apply to letters such as �, �, �, and �? Thanks in advance.