The principle phonation types in English

  

Date Posted: 10/21/2012 4:16:24 PM

Posted By: vann  Membership Level: Gold  Total Points: 1015

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Phonation is the sound made by the vibration of vocal folds modified by razonant of vocal tract. This modification results in different status of glottis, for example open glottis, vibrating state of glottis, narrowed glottis, slightly open state of glottis and finally closed glottis.
These different states of glottis result in different phonation types. The main phonation types include voiced phonation and voiceless phonation.
1.0 VOICELESS PHONATION TYPES
a. Nil
Realized either by blocking the air flow from the lungs with fully abducted vocal folds or with vocal folds widely abducted and wide opening of the glottis, when the air flow laminar in both cases no sound is generated and no acoustic energy is injected in the vocal tract.
Voicelessness at higher flow speed causes turbulence even with widely abducted vocal folds, this type of phonation is called breath.example;pronunciation of / h / sound at the beginning of the word like German ‘hant’ where the volume velocity flow can reach 1000cc/s.
b. Whisper.
This is characterized by a triangular cartilaginous glottis (shape of an inverted y) adductive tension is very low and medial compression as well as longitudinal, are moderately high.
Whisper sound quality is produced through turbulence generated by friction of the air in and above the larynx with vocal folds vibrating.
Apart from the rather seldom linguistic uses, whispers are widely used paralinguistically to signal secret or and confidentiality.

2.0 VOICED PHONATION TYPE.
a. Modal voice phonation.
In the normal case the vibration of the vocal folds is periodic with full closing of the glottis so that no audible friction voices are produced when air flow through the glottis. All muscular adjustments are on a moderate level and the frequency of vibration as well as loudness are in the lower to mid part of the range usually used in conversation. The modal phonation of a male speaker occurs at an

average of 120Hrtz while for a female speaker it occurs at about 220Hrtz.
For voiced sounds glottis are closed or nearly closed whereas for voiceless sound it is wide open, actually the distance between the folds amounts to only a fraction of a millimeter, the degree of opening and its timing is relative to the articulatory gesture and depends on the phonetic environment of the generated sound. The average flow rate is between 100 to 350 cc/s.
a. Creaky phonation/vocal fry
It is also produced when vibrating vocal folds but at a low frequency are strongly adducted and of weak longitudinal extension. Both these cases cause the vocal folds’ thickening, additionally, they may come in contact with the fault fold creating an unusual thick and slack structure. The resulting low tension and heavy vibrating mass are responsible for slower and irregular vibration. Both sub-glottal pressure and glottal air flow are lowered compared to modal phonation. The speed flow is about 12 to 20 cc/s and the frequency ranges between 250to 50 Hertz.
a. Breathy voice phonation.
It is normally regarded a compound phonation type(voiceless and modal) but it is regarded or viewed at as independent phonation type because of diverse adjustments of laryngeal structures in comparison with other phonation modes.
Muscular tension is low with minimal adductive tension, weak medial compression and medium longitudinal tension of vocal folds. Vocal folds vibration is inefficient and because of the incomplete closure of the glottis, a constant glottal leakage occurs which causes the production of audible friction noise. Air flows through the vocal folds at a high rate. The vibration frequency is just below the value typical of the modal voice,
Breathy voices differ from the voiced whisper because of the weaker medial compression and the smaller degree of the voicing effort. However, as pointed out by Laver (1980) there is no clear perceptual boundary between breathy voice and whisper.

b. Harsh phonation
This is due to the very strong tension of the vocal folds (especially the medial compression and adductive tension) which results in an excessive approximation of the vocal folds. When the whole larynx is subjected to those extremely high tensions, the upper larynx becomes highly constructed with the ventricular folds pressing on the surface of the vocal folds, making their vibration ineffective. Harsh phonation is therefore irregular in both circle duration and amplitude. The characteristic fundamental frequency is above Hertz.
c. Falsetto phonation
The frequency of vibration in falsetto phonation is noticeably higher than in modal voice. The vocal folds are stretched longitudinally thus becoming relatively thin. Consequently, the vibrating mass is smaller and the generated tone higher. The adduction of the folds is high and medial compression is also strong. The glottis often remains slightly open, resulting in low sub-glottal pressure. [Due to constant glottal leakage] and the generation of the audible friction noise component.

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