SAMIAM, are you noticing any sound coming from the tree.
If you take you index finger and thumb and make a pinching motion on a pair of jeans allowing your finger nails to contact the jeans, it will make a sound that is very similar to the sound of a wood devouring insect or grub.
There is a particular insect that when it attacks an evergreen, it causes exactly what you describe. I do not want to mention it as it would be truely a sad day if they have made it here.
If you cannot get someone, give these guys a call, they have a location in Meredith.
http://www.chippersinc.com/ They have some extremelely knowledable folks on the payroll and truely care about keeping trees healthy.