She also had a loss in overall vocal range from the first to the fifth day (~2 semitones) and exhibited evidence of abnormal supraglottal tension during phonation under videostroboscopy.
You did exhibit a mild degree of supraglottal compression both in the medial-lateral and anterior-posterior directions.
It is known that supraglottal inertive reactance and subglottal compliant reactance both lower the phonation threshold pressure, thereby producing a larger amplitude of vocal fold vibration (and greater rate of change of glottal flow) than would be predicted by linear source-filter theory.
Returning to Figure 1, the subglottal and supraglottal vocal tract airways (from bronchial bifurcation to lips) are about 25 cm long, compared to about 33 cm in a typical male airway.
Supraglottal inertance is shown above the horizontal zero reference line in filled horizontal bars.
The supraglottal formants are located where the inertance suddenly collapses to zero and the subglottal formant frequencies are where the compliance begins its downward thrust from zero.
In this way, the larynx is more or less forced to make the changes for head voice without the interference of supraglottal
When the shaded areas are above the reference line, we have supraglottal inertance, which is beneficial.
Note that 2[F.sub.0] is reinforced by supraglottal inertance for the singing /i/, but not for the speaking /i/.
inertance is known to support vocal fold oscillation by lowering the phonation threshold pressure.
In speech and singing, the supraglottal
cavities (i.e., the pharyngeal cavity, the buccal cavity, and in some cases, the nasal and labial cavities) in which the laryngeal sound resonates.
* During vowel production, the positions taken on by the vocal organs give the supraglottal
cavities the characteristic shape and volume of the vowel in question.