" 
 ::Ha! Greek language doesn't specialise in what it calls barbaric (hard) sounds. (Actually, etymologically, Barbarian is someone who's tongue makes an incomprehensible to Greeks bar-bar sound!) We don't have B, we don't differentiate it from MP or MB or plain B sounds either. The same we don't have D, (we write NT) and do not differentiate it from NT or ND or plain D. Every Greek word can be pronounced either way, but usually it is the softest (mp and nt) sounds that prevail. 
 ::For stress, no it's not lengthened or somthing. I'll give you an example: The English word democrátic versus the French pronounciation democratíque. The first has a stress in A and the second in I. Greek language needs that accent where the stress is, do show the reader where to stress, because we generally use more vowels and less consonants.  "