drumming vs pitter-patter

drumming

noun
  • A noise resembling that of a drum being beaten. 

  • In many species of catfish, the sound produced by contraction of specialized sonic muscles with subsequent reverberation through the swim bladder. 

  • The act of beating a drum. 

pitter-patter

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

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