How to remove the his from audio tracks that you paste?

Hey guys, Im working on a project that i have to keep a sound going for awhile. What im doing is taking the sound and pasting it to the end of the track repeatedly. Upon play back it has a redundant his each time the tracker passes a clip i pasted on. Im really new to audition so this may be a newb question so im sorry ahead of time. I have tried the declicker and a few noise reduction effects but im not getting the results i wanted. Is there an easy way to blend these tracks so they sound fluid? Maybe im going about this all wrong? im not sure. I hope someone can help me out.. Thank you in advance.