Is the nock point higher or lower if you shoot 3 under?
I was thinking of changing in 2013 because my stand set will have a pretty consistant shot distance.
Ive experimented in the past and shoot better but my bow sounds lounder?
any reason it does?

Its my understanding that if the bow is tillered for split finger, it can be slightly louder when shot 3 under.  Usually ideal tiller for 3 under is even.

I shoot three under and my nock point is 1/8" above center. I can hear no discernible difference between it and split finger so I cannot help you there.

I've found on all the bow I've shot(which is a lot of bows as I buy and sell a lot) that 3 under is always a little bit louder. Your nocking point will be higher for 3 under.

3 under tends to be a touch louder regardless how the bow is tillered, in my experience. With a bit of tuning and proper arrow weight the difference is negligible.

Yep, higher nocking pt. I have a recurve that is 3/4" high for wood arrows.

I have always shot a high nock. 3/4" I switched to three under and did not change the nock position at all.

3 under will have a little higher nock point for most people , as for noise may just sound a little louder to you as the arrow is a closer to your ear now . I have video of myself shooting split and 3 under and dont hear a difference. Have someone stand behind  you and try it both ways then see if they think there is a difference .

I agree with the others, three under is always a little louder than split for me.  

I usually end up with my nock point about 3/4" - 7/8" above level for three under.  Once you find the right nock point by bare shaft tuning the bow will be pretty quiet, just not quite as quiet as it would be shooting split finger...at least for me.