yeah..the chirping is totally normal right before they hatch...because now their beaks are in the air cell, breathing air for the first time and now they can chirp!!
the chirping is not only normal, its GOOD....nothing to worry about
you DONT TURN at this point...its not needed anymore, and can only confuse the chick by turning the egg now...his beak is pointed up and ready to pip and hatch..if u start turning now, you might get him pointed down and disoriented...and he has a tough job ahead of him already to get himself hatched
so just leave those eggs ALONE like everyone is telling you....DONT OPEN THE INCUBATOR...your humidity should be high right now...like 65-70%, even higher is OK...if it is below 60, I would be trying to get it higher now, before they start to hatch, which could happen at any time....
the way I did that WITHOUT opening the incubator, is i taped a straw to the end of a funnel, and stuck the straw thru the air holes in the top of the bator, and aimed the straw, and poured a little bit of warm water into the funnel, and thru the straw and into the channels on the bottom of the bator, to make sure they are all full
so right now, make sure your temp and humidity are good...DONT OPEN the bator...and just WAIT and let them hatch..let us know how it's going!