pitter-patter vs vibration

pitter-patter

noun
  • A soft, percussive sound, as of tiny feet, or of rain on a rooftop. 

vibration

noun
  • A single complete vibrating motion. 

  • An instinctively sensed emotional aura or atmosphere. 

  • A vibrational energy of spiritual nature through which mediumistic and other paranormal phenomena are conveyed or affected. 

  • The act of vibrating or the condition of being vibrated. 

  • Any periodic process, especially a rapid linear motion of a body about an equilibrium position. 

How often have the words pitter-patter and vibration occurred in a corpus of books? (source: Google Ngram Viewer )