deterrent vs impediment

deterrent

noun
  • Something that deters. 

adj
  • Serving to deter, preventing something from happening. 

impediment

noun
  • A hindrance; that which impedes or obstructs progress. 

  • Baggage, especially that of an army; impedimenta. 

  • A disability, especially one affecting the hearing or speech. 

How often have the words deterrent and impediment occurred in a corpus of books? (source: Google Ngram Viewer )