phonation vs vocalise

phonation

noun
  • The process of producing vocal sound by the vibration of the vocal folds that is in turn modified by the resonance of the vocal tract. 

vocalise

noun
  • A vocal exercise performed by singing one or more vowels without actually forming any words. 

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