First, there is the sound the audience hears: as alluded above, this is actually as many voices as there are ears both because each person is in a different space with its own acoustic properties, and each senses the music differently because of physical variation and all the mental factors related to experience, age etc etc.  However, we can still group them together with respect to the sound coming out of the violin - they will all hear something similar.

 

Second, there is the sound that comes out of the violin under your chin.  This is a distinct voice since only the person that close can hear all the tones, overtones of the music - and all the scrapes and crunches that are hopefully below the sound level of the audience. 

 

And then there is the third voice that has only just become apparent to me.  And that is the one inside your head: what you imagine the sound to be.  I'm actually writing this because I discovered that for me this voice is far louder than the one coming out of the violin.  Thus, my playing is what I imagine it to be rather than what it is.  This might explain why when I play something and then listen back to it on the tape recorder its often so different - the playing has the emotional content but not the technical perfection that I thought I heard! 

 

What’s so fascinating about this is that I realize that all three voices are critical.  Obviously, the audience one needs no explanation: you have to play in a way that the audience will get the cream, as it were. To do this you must hear the second voice, that of the instrument itself, to be in tune and to adjust tone and tempo. I was beginning to think that the third voice, the one in your head, is a bane – but it is also the biggest blessing. Its only just dawned on me that this voice is the one that gives playing musicality: its what you are intending to say and hence what you are projecting onto the instrument and audience.