Waveform recognition of the modes
Looking at the images of the waveform we can confirm that it seems possible to identify the modes by the Laryngograph waveforms to a certain extend. There are some extend patterns in the waveform that could be used to identify the modes. (See Waveform recognizion in Neutral, Curbing, Overdrive and Edge)
You can see the green trace is the Laryngograph changes, where you can see the very distinctive wave patterns for the different type of modes.
Waveform in vocal breaks
A study was recording the laryngograph ELG signal with the acoustic signal using the speech studio program for the analysis.
This is the type of output you get with the speech studio program. You can see the spectrogram with fx. Overdrive and see that the spectrum changes when you are breaking to another mode.
The green line is the fx trace and you can see it follows the waveforms for the modes which is the same for the contact quotient (Qx) (the purple line).
The little frame in the middle picture the magnified view, with 2 lines. The top one is a blue line that is the speech signal, the one underneath is the laryngograph line, the electroglottal measure, that gives us a measure of the vocal folds activity. Here you see a nice and regular waveform when the mode is sustained.
On the sustained notes you can’t see much activity, just a waveform that indicates which mode is being used, and then when the mode changes you’ll see a matching change in the waveform according to the new mode. Dependig on the distinctness of the break a flageolet waveform is also displayed.
Contrary to an uncontrolled constriction where everything seem to constrict and you see irregular laryngograph waveform, here you see the laryngograph waveform change according to the vocal mode. By displaying the change in waveform from mode to mode we asume that the vocal folds underneath the change of the laryngeal gestures are vibrating regularly.
This information comes from a study Visual Vocal Mode Test Study on stills, with the title ‘Laryngeal gestures and Laryngograph data associated with the four vocal modes as described in the Complete Vocal Technique method of singing teaching’. This study was presented by Cathrine Sadolin and Julian McGlashan at BVA ‘Choice for voice’ conference in London, England, 2010.
This study with the title ‘To Break or not to break – that is a choice!’ was presented by Cathrine Sadolin & Julian McGlashan at Pevoc 9 (Pan-European Voice Conference) Marseille, France, August 2011.