Noise "appearing" in silent spaces on import

My students are creating podcasts in my class. One of my students conducted an interview which sounds fine when she plays it for me from the file she saved on her computer.  However, once she imports it into Audition, the silences-- or rather, places where conversation naturally paused or a speaker paused for a second or two-- are filled with a scratching noise that sort of sounds like someone is moving around paper or an object being moved across a table.  I'm not sure why this is happening or how to fix it so it doesn't happen on import. Noise reduction hasn't done anything to fix it within Audition either. 

I know how to remove these "scratchy" sections by clipping them out-- but that's rather painstaking for her given the recordings are long (and, she has 3 separate interview recordings which are problematic). 

Any thoughts on why this is happening and/or a less painstaking way to get rid of the scratching noise where pauses in speech are naturally occuring? 

Thank you!