asynchronization vs simultaneity

asynchronization

noun
  • The condition of being asynchronous or of being asynchronized 

simultaneity

noun
  • More than one complete musical texture occurring at the same time. This first appeared in the music of Charles Ives, and is common in the music of Conlon Nancarrow, and others. 

  • The quality or state of being simultaneous; simultaneousness. 

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