So a small study was done on a Rossini(leggiero) tenor. the way the Rossini tenor traditionally produces his high notes was in a sort of "modified falsetto" or something we might call "mixed voice," "head voice," or "pharyngeal voice" in contemporary singing circles today. The researcher refers to this as "voce faringea."
The fascinating thing about this result of this research was that, even though the technique used was a "modified falsetto" type of approach.. the EGG-waveform is similar to that of "chest voice" (laryngeal mechanism 1.) However, the sound is produced in a "reinforced falsetto" type of a mechanism (M2.)
Here are the audio samples with associated EGG data from the study!
The full paper is also available as a PDF "Parameters of Flow Glottogram and EGG for Vocal Registers – Modal, Falsetto and voce faringeal."