Article

Phonation threshold pressure measurement with a semi-occluded vocal tract.

National Center for Voice and Speech, The Denver Center for the Performing Arts, Denver, CO, USA.
Journal of Speech Language and Hearing Research (Impact Factor: 1.93). 09/2009; 52(4):1062-72. DOI: 10.1044/1092-4388(2009/08-0110)
Source: PubMed

ABSTRACT The purpose of this article was to determine if a semi-occluded vocal tract could be used to measure phonation threshold pressure. This is in contrast to the shutter technique, where an alternation between a fully occluded tract and an unoccluded tract is used.
Five male and 5 female volunteers phonated through a thin straw held between the lips. Oral pressure behind the lips was measured. Mathematical predictions of phonation threshold pressures were compared to the measured ones over a range of frequencies.
It was shown that, for a 2.5-mm diameter straw, phonation threshold pressures were obtainable over a 2-octave range of fundamental frequency by all volunteers. In magnitude, the pressures agreed with the 0.2-0.5 kPa values obtained in previous investigations. Sensitivity to viscoelastic and geometric properties of the vocal folds was generally not compromised with greater oral impedance, but some differences were predicted theoretically in contrast to an open mouth configuration.
Because phonation threshold pressure is always dependent on vocal tract interaction, it may be advantageous to choose an exact and fixed oral semi-occlusion for the measurement and interpret the results in light of the known acoustic load.

2 Bookmarks
 · 
164 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract The occurrence of intermittent aphonia, perceived as sudden interruptions of voicing in connected speech, often reflects high stiffness of the vocal fold mucosa as part of a voice disorder. This retrospective study aimed to investigate the overarching hypothesis that the aphonic instances in voices with intermittent aphonia are not totally randomly appearing, but related to syllable stress and phonetic context. Recordings of 31 dysphonic patients with intermittent aphonia reading a standard text were analyzed perceptually. All vowels of the text were labelled and categorized with regard to syllable stress and character of the phoneme preceding the vowel. The occurrence of aphonic instances within each syllable category was analyzed. Four different hypotheses were formulated and analyzed by the non-parametric Wilcoxon's signed-ranks test. The results showed a significantly higher occurrence of aphonic instances in unstressed syllables as opposed to stressed, in vowels following an unvoiced phoneme as opposed to a voiced, and in vowels following two or more unvoiced phonemes as opposed to one unvoiced phoneme. No significant difference was found between vowels following aspirated stops [p], [t], [k] as opposed to unaspirated stops [b], [d], [g]. The findings support the theory that both physiological and functional aspects may contribute to the phenomenon of intermittent aphonia.
    Clinical Linguistics & Phonetics 03/2014; · 0.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the immediate effects of humming and subsequent um-hum phonation on the computed parameters of electroglottographic (EGG) signals in muscle tension dysphonia (MTD) patients and nondysphonic speakers.
    Journal of voice: official journal of the Voice Foundation 06/2014; · 0.95 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This contribution is aimed to provide material that can be used to develop more realistic physical models of voice production. The experimental methodology and the results of measurement of subglottal, oral (substitute for subglottic) and acoustic air pressure (captured at a distance of 20 cm in front of the subject's mouth) are presented. The data were measured during ordinary speech production and when the acoustic impedance and mean supraglottal resistance were raised by phonating into differently sized tubes in the air and having the other end submerged under water. The results presented in time and frequency domain show the physiological ranges and limits of the measured pressures in humans for normal and extreme phonation. Keywords: Biomechanics of voice, measurement of oral pressure, voice exercises, phonation into tubes.