A good example of the voice/inflection thing can be seen in the episode Parturition, S2 E7. Listen to the Doc/EMH speaking to Kes in sick bay after Tom & Neelix leave for the planet, he sounds irritatingly pompous his voice lowered, jaw clenched. A stunning homage to arrogant a-holes everywhere. When he returns to something close to his natural speaking voice between season 3 & 4 it's a welcome fix. I think most would agree the character is better served in his natural voice & mannerisms.