impact vs percussion

impact

noun
  • The striking of one body against another; collision. 

  • A significant or strong influence or effect. 

  • A forced impinging. 

  • The force or energy of a collision of two objects. 

verb
  • To stamp or impress onto something. 

  • To collide or strike, the act of impinging. 

  • To significantly or strongly influence or affect; to have an impact on. 

  • To compress; to compact; to press into something or pack together. 

percussion

noun
  • The collision of two bodies in order to produce a sound. 

  • The detonation of a percussion cap in a firearm. 

  • The tapping of the body as an aid to medical diagnosis. 

  • The sound so produced. 

  • The repeated striking of an object to break or shape it, as in percussion drilling. 

  • The outer side of the hand. 

  • The section of an orchestra or band containing percussion instruments; such instruments considered as a group; in bands, may be separate from drum kits. 

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