clicks and pops could be considered more of a soundcard issue or improper recording. Rather, other times it could be a result of a faulty mic, mic cable or mic line input.
Check to see if your sound files are too loud (past the distortion threshold, above 0db), try different inputs if you have them, and/or try different mics.
If all else fails, there are certain software packages designed to eliminate that, but it really shouldn't have to come to that.
Hope that helps