Phonation - State of The Glottis

State of The Glottis

In linguistic phonetic treatments of phonation, such as those of Peter Ladefoged, phonation was considered to be a matter of points on a continuum of tension and closure of the vocal cords. More intricate mechanisms were occasionally described, but they were difficult to investigate, and until recently the state of the glottis and phonation were considered to be nearly synonymous.

If the vocal cords are completely relaxed, with the arytenoid cartilages apart for maximum airflow, the cords do not vibrate. This is voiceless phonation, and is extremely common with obstruents. If the arytenoids are pressed together for glottal closure, the vocal cords block the airstream, producing stop sounds such as the glottal stop. In between there is a sweet spot of maximum vibration. This is modal voice, and is the normal state for vowels and sonorants in all the world's languages. However, the aperture of the arytenoid cartilages, and therefore the tension in the vocal cords, is one of degree between the end points of open and closed, and there are several intermediate situations utilized by various languages to make contrasting sounds.

For example, Gujarati has vowels with a partially lax phonation called breathy voice or murmured, while Burmese has vowels with a partially tense phonation called creaky voice or laryngealized. Both of these phonations have dedicated IPA diacritics, an under-umlaut and under-tilde. The Jalapa dialect of Mazatec is unusual in contrasting both with modal voice in a three-way distinction. (Note that Mazatec is a tonal language, so the glottis is making several tonal distinctions simultaneously with the phonation distinctions.)

Note: There was an editing error in the source of this information. The latter two translations may have been mixed up.

Javanese does not have modal voice in its stops, but contrasts two other points along the phonation scale, with more moderate departures from modal voice, called slack voice and stiff voice. The "muddy" consonants in Shanghainese are slack voice; they contrast with tenuis and aspirated consonants.

Although each language may be somewhat different, it is convenient to classify these degrees of phonation into discrete categories. A series of seven alveolar stops, with phonations ranging from an open/lax to a closed/tense glottis, are:

The IPA diacritics under-ring and subscript wedge, commonly called "voiceless" and "voiced", are sometimes added to the symbol for a voiced sound to indicate more lax/open (slack) and tense/closed (stiff) states of the glottis, respectively. (Ironically, adding the 'voicing' diacritic to the symbol for a voiced consonant indicates less modal voicing, not more, because a modally voiced sound is already fully voiced, at its sweet spot, and any further tension in the vocal cords dampens their vibration.)

Alsatian, like several Germanic languages, has a typologically unusual phonation in its stops. The consonants transcribed /b̥/, /d̥/, /ɡ̊/ (ambiguously called "lenis") are partially voiced: The vocal cords are positioned as for voicing, but do not actually vibrate. That is, they are technically voiceless, but without the open glottis usually associated with voiceless stops. They contrast with both modally voiced /b, d, ɡ/ and modally voiceless /p, t, k/ in French borrowings, as well as aspirated /kʰ/ word initially.