pitter-patter vs pulsation

pitter-patter

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

pulsation

noun
  • A single beat, throb or vibration. 

  • The regular throbbing of the heart, an artery etc. in a living body; the pulse. 

  • Any rhythmic beating, throbbing etc. 

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