I just noticed today that bow is louder than normal, or i just havent shot very much lately and it seems that way.  I always thought of my Bob Lee being pretty quiet but maybe i was wrong, it sounds louder than usual.

Yes.  your brace and or nock point could have slipped too.

I checked brace and nock point and it's were it is suppose to be.

If your old string breaks, it'll make your bow really loud.

Something that happened to me over time my yarn silencers were getting smaller and smaller.  I cut the loops, then I would lose some fibers on every shot.  Eventually my bow needed more weight on the string so I redid my yarn silencers but did not cut the loops.  Problem solved for me.

Strings only last so long...just like tires. Even if they have tread, they can still be worn out.

I had a perfectly fine looking string break on me once. It will NEVER happen again. If your string has been around a while, change it...regardless of whether it has become noisy or not.

For the cost of a new string, you cannot justify waiting for a failure.

It could be your string silencers.A friend of mine had the same problem.Turned out his beaver fur string silencers were coming loose.We could hear a vibration sound when he would shoot.He unstrung the bow and pulled the ends tight.Strung it back up and shot,the noise was gone.

With time and use they became noiser. Most bow makers advise you to change your string after one year or 10,000 shots