I see many people talking how the "voice" of Red John is unimportant,but I disagree...we heard this voice ourselves couple of time while listening Red John talking to Patrick(season 2 meeting,season 4 car scene,season 6 telephone talk)...also Rosalind Harker spoke about his soft voice and little girl told Patrick the man who draw a smiley face on her hand had an odd voice so it has been a important clue during show...I feel like they need to explain the voice to us,either Red John puts an odd voice or he uses some kind of voice box but it would be disappointing if the voice would just been ignored...and I would really love to see Red John using that voice when we finally see him as who he is. Cheers!