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At least 19 recordsLinked to original sources
PubMed2006

Early acquisition of esophageal phonation following tracheoesophageal phonation.

CONCLUSIONS: Tracheoesophageal phonation appears to participate in early acquisition of esophageal phonation, which remains the preferred method of voice restoration among patients. Further studies into factors predicting and mechanisms underlying acquisition of esophageal phonation among alaryngeal patients may provide information facilitating superior quality of life. OBJECTIVE: The aim of this study was to examine early acquisition of esophageal phonation following tracheoesophageal phonation, and underlying mechanisms and preferred phonatory methods for alaryngeal patients who master both tracheoesophageal and esophageal phonation. PATIENTS AND METHODS: Subjects comprised 44 alaryngeal patients and were divided into three groups: group A (n=13), esophageal phonation alone; group B (n=21), tracheoesophageal phonation alone; and group C (n=10), patients who acquired esophageal phonation after learning tracheoesophageal phonation. RESULTS: The results indicated that acquisition of tracheoesophageal phonation significantly accelerated acquisition of esophageal phonation to 59.3 days from 184.6 days. Patients in group C stopped tracheoesophageal phonation and predominantly used esophageal phonation. No factors predicting acquisition of esophageal phonation were identified among patients who had mastered tracheoesophageal phonation, including age at time of surgery, irradiation, neck dissection, acquisition time of tracheoesophageal phonation, and maximum phonation time of tracheoesophageal phonation. No evidence of air leakage through the shunt during esophageal phonation was noted in group C.

Esophagus↗
PubMed1994

Phonation time, phonation volume and air flow rate in normal adults.

The purpose of this study was to determine the average phonation time, phonation volume and air flow rate, as well as the relationship between each of these parameters during two conditions (normal and deep breaths). Researchers expect to use these averages in screening of voice disorders. One hundred and three subjects, 67 males and 36 females, were studied. The instruments were a 9 liter respirometer, a tape recorder and a stop watch. The results indicated that the parameters for males were significantly greater than those for females. In addition, the findings suggested that the values of mean phonation time, phonation volume and air flow rate during deep breath were significantly greater than those during normal breath (p < 0.05). The phonation time was inversely related to the air flow rate. However, there was a positive relationship between phonation time and phonation volume, as well as between phonation volume and air flow rate. The findings supported our hypothesises.

Female↗
PubMed1999

Phonation threshold pressure measurements during phonation by airflow interruption.

OBJECTIVE/HYPOTHESIS: Most methods to measure phonation threshold pressure (PTP) are clinically impractical because they are invasive. This report concerns an airflow interruption system developed to allow noninvasive estimation of (PTP) at different levels of vocal intensity. An estimation of PTP was made for normal subjects with normal larynges and no voice complaints and for individuals who had dysphonia associated with vocal polyps to compare the estimated minimal pressure across the glottis that was required to sustain phonation in the two conditions. STUDY DESIGN: This was a methodological study designed to measure an unanticipated PTP from a subject. METHODS: Subjects sustained a constant tone and the airflow was directed into a section of pipe with an airtight mask over the mouth and nose. The airflow, intramask pressure, and intensity of the acoustic output were recorded. A PTP was predicted from a difference between an estimate of the subglottal pressure and the vocal tract pressure at the point that phonation ceased after interruption of airflow. Eleven control subjects and 13 patients with vocal fold polyps were studied. In each population there were eight men and five women. The individuals in the group with vocal fold polyps averaged 39 years of age, and the control subject group averaged 49 years of age. Normal subjects produced a steady vowel /a/ at 75, 80, and 85 dB. Patients with polyps were unable to sustain phonation at these levels but were able to produce phonation at 65, 70, and 75 dB. The validity of the system was tested using a laryngeal model and in a patient with a normal larynx and voice who had a tracheotomy (placed for sleep apnea syndrome) which allowed direct measurement of subglottal pressure. RESULTS: The measured mean PTP levels (with standard deviation [SD]) for the control subjects were 2.38 (1.273), 2.67 (1.879), and 2.98 (2.23) cm H2O at 75, 80, and 85 dB, respectively. The measured mean PTP levels (with SD) for the patients with polyps were 4.79 (2.67), 5.85 (2.34), and 7.37 (3.26) cm H2O at 75, 80, and 85 dB, respectively. The differences in mean PTP between groups at 75, 80, and 85 dB were significant at P = .013, P = .017, and P = .010, respectively. CONCLUSIONS: The estimations of PTP for patients with vocal fold polyps were significantly higher than for the control subjects at three phonation levels.

Adult↗
PubMed2002

Regulating glottal airflow in phonation: application of the maximum power transfer theorem to a low dimensional phonation model.

Two competing views of regulating glottal airflow for maximum vocal output are investigated theoretically. The maximum power transfer theorem is used as a guide. A wide epilarynx tube (laryngeal vestibule) matches well with low glottal resistance (believed to correspond to the "yawn-sigh" approach in voice therapy), whereas a narrow epilarynx tube matches well with a higher glottal resistance (believed to correspond to the "twang-belt" approach). A simulation model is used to calculate mean flows, peak flows, and oral radiated pressure for an impedance ratio between the vocal tract (the load) and the glottis (the source). Results show that when the impedance ratio approaches 1.0, maximum power is transferred and radiated from the mouth. A full update of the equations used for simulating driving pressures, glottal flow, and vocal tract input pressures is provided as a programming guide for those interested in model development.

Adult↗
PubMed2002

Transcutaneous PCO(2) monitoring with hyperventilation during phonation in vocal cord paralysis.

OBJECTIVE: Hyperventilation during phonation is one of the causes of fatigue in-patients with vocal disorders. METHODS: The transcutaneous (tc) PCO(2) during phonation in 8 normal subjects and 12 patients with unilateral vocal cord paralysis was measured. Cases were further divided into two groups by the degree of the tcPCO(2) decrease during phonation. Patients with a tcPCO(2) decrease less than 3.4 mmHg during phonation were classified as group 1 (G1). Patients with a tcPCO(2) decrease larger than or equal to 3.4 mmHg during phonation were classified into group 2 (G2). RESULTS: The average changes in tcPCO(2) in the G1 cases was not significantly different from that in normal subjects. The decrease in tcPCO(2) during phonation in the six G2 cases was 10.7+/-6.2 mmHg, and was significantly different from that in normal subjects (P<0.01, t-test). The decrease of tcPCO(2) during phonation in both G1 and G2 cases improved significantly after surgical treatment. Easy fatigability during phonation in two G1 cases and five G2 cases improved. CONCLUSIONS: The decrease in tcPCO(2) during phonation in cases of unilateral vocal cord paralysis is well correlated with easy fatigability. It is clinically useful to classify cases into two groups using the criteria of a less than 3.4 mmHg or larger than or equal to 3.4 mmHg decrease in tcPCO(2). These results also suggest that hyperventilation is one major cause for easy fatigability during phonation in cases with unilateral vocal cord paralysis. TcPCO(2) changes during phonation are useful in evaluating hyperventilation and the effect of treatment.

Adult↗
PubMed2003

Nonlinear dynamics of phonations in excised larynx experiments.

Nonlinear dynamic methods including correlation dimension and Lyapunov exponents are applied to quantitatively analyze phonations in excised larynx experiments. Irregular phonations are typically characterized by aperiodic waveforms and broadband spectra. Finite correlation dimensions and positive Lyapunov exponents of irregular phonations demonstrate the existence of chaos in excised larynx phonations. Furthermore, the correlation dimension, maximal Lyapunov exponent, jitter, shimmer, and peak prominence ratio are used to statistically distinguish irregular phonations from normal phonations. The correlation dimension and maximal Lyapunov exponent indicate a significant difference between irregular and normal phonations; however, jitter, shimmer, and peak prominence ratio do not reveal such a significant difference and thus are unsuitable to differentiate between irregular phonations and normal phonations. These findings might potentially assist investigators in understanding rough phonations and developing clinically valuable methodologies for the diagnosis of voice disorders.

Animals↗
PubMed1994

An in vivo canine model for the study of phonation physiology by midbrain stimulation.

A versatile in vivo canine model is indispensable in studying the phonation function of the larynx. In this study, we attempted to build an in vivo phonation model in anesthetized dogs using stereotaxic electrical stimulation at a specific area in the midbrain. In each of the eight animals in this experiment, evoked phonation was successfully elicited by stimulating sites in the area ranging from 9 to 11 mm anterior, 3 to 5 mm lateral and 5 to 16 mm dorsal to the ear bar zero. This area was at the lateral border of the periaqueductal gray in the midbrain. The evoked-phonation process involved electrical stimulation of sites in this area, resulting in consistent responses by respiratory and laryngeal musculature accompanied by phonation. The evoked phonation could be consistently repeated. Different pitches of phonation were elicited by slightly moving the stimulation spots in this area. During evoked phonation, the subglottic aerodynamic power and individual laryngeal muscle action could be modified to study the effects of a single factor on the phonation process. The neuromuscular action for the control of phonation and the mechanical properties of the vocal folds can be investigated using an in vivo canine model.

Animals↗
PubMed2001

Acoustic comparison of vowel articulation in normal and reverse phonation.

Acoustic characteristics of the vowels /i,u,a/ produced by adult females and males during normal phonation were compared with the same vowels produced on deliberate ingressive airflow (i.e., "reverse" phonation). Results of the analysis revealed the average fundamental frequency (F0) of reverse phonation to be significantly higher than the corresponding normal phonations. There were no significant differences noted in the vocal tract resonance (F1 and F2 frequency) values for /i/ during normal and reverse phonation. However, the F1 values for /a/ were significantly lower, and the F2 values for /u/ significantly higher, during reverse phonation. The results are discussed with regard to differences in the articulatory control of the speech mechanism during reverse phonation as compared to normal expiratory phonation. Also discussed are the implications of using reverse phonation as a voice management technique.

Adult↗
PubMed2005

Some physiological correlates to regular and irregular phonation at the end of an utterance.

This article examines respiratory and acoustic events at the ends of utterances that coincide with the end of a breath. All utterances end with a vowel. Between the start of the final fall in signal amplitude and the end of phonation, the alveolar pressure falls by 1.2-2.6 cm H2O, on average, and glottal area increases by a factor of 4.0 (median). The mean glottal area at the end of phonation ranges from 9.6 to 13.5 mm2 across subjects. Physiological correlates are examined for utterances that end with regular and with irregular phonation. Irregular phonation is usually produced with brief intervals of adduction followed by longer intervals of abduction and/or with incomplete closure of the folds. This physiological correlate to irregular phonation is not consistent with descriptions of vocal fry or creaky voice in which the vocal folds are tightly adducted over most of the cycle. The rise in average glottal area and drop in alveolar pressure were similar for utterances that ended with regular phonation and those that ended with irregular phonation. These data suggest that a similar phonation-ending gesture underlies both groups of utterances. This gesture includes abduction of the vocal folds and a drop in alveolar pressure.

Adult↗
PubMed1984

Duration of sustained phonation in kindergarten children.

Maximum sustained phonations of the vowels [a], [u] and [i] were obtained from 160 kindergarten children with a mean age of approximately 6.2 years. Subjects were grouped by sex and by the presence or absence of a voice disorder. Stop watch measurements of each subject's maximum phonations were compared with graphic level recorder measurements of those phonations . The results indicated that (1) the factor of sex had no significant effect on maximum phonation times; (2) the factor of voice group (non-voice-disordered/voice-disordered) did result in a significant effect (P less than 0.01) with the voice-disordered group achieving shorter phonations than the non-voice-disordered group; (3) the phonation times obtained from the two measurement procedures correlate significantly (P less than 0.05). Results also suggest that the vowel effect on maximum phonation time was significant (P less than 0.05) for both groups. The vowel [i] was phonated significantly longer than either [a] or [u] for males and females in both groups.

Child↗
PubMed1996

Vocal fold vibration in simulated head voice phonation in excised canine larynges.

In order to establish precise vibratory patterns and their clinical implication for phonation, the mode of vibration of the vocal folds around the time of register transition in excised canine larynges was analyzed multi-directionally according to various acoustic parameters. Phonation was simulated by artificially tensing the cricothyroid muscles. Vibration of the vocal folds around the time of register transition was filmed from above using ultra-high-speed cinematography and in a frontal plane using X-ray stroboscopy. Acoustic parameters included subglottic pressure, pitch, intensity and tension and were recorded simultaneously during register transition. The fundamental vibration patterns observed during vocal phonation were the same as that involved in chest voice phonation in excised canine larynges, with respect to the traveling wave of the vocal fold vibration. Changes in the physical properties of the vocal folds were considered to occur at register transition. These changes were probably strongly dependent upon changes in the structure of the lamina propria. Head voice phonation requires adaptability of the lamina propria and is less efficient than chest voice phonation. Hence, head voice phonation would be one method for assessing the condition of the vocal folds.

Animals↗
PubMed2005

A quantitative study of the medial surface dynamics of an in vivo canine vocal fold during phonation.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to measure the medial surface dynamics of a canine vocal fold during phonation. In particular, displacements, velocities, accelerations, and relative phase velocities of vocal fold fleshpoints were reported across the entire medial surface. Although the medial surface dynamics have a profound influence on voice production, such data are rare because of the inaccessibility of the vocal folds. STUDY DESIGN: Medial surface dynamics were investigated during both normal and fry-like phonation as a function of innervation to the recurrent laryngeal nerve for conditions of constant glottal airflow. METHODS: An in vivo canine model was used. The larynx was dissected similar to methods described in previous excised hemilarynx experiments. Phonation was induced with artificial airflow and innervation to the recurrent laryngeal nerve. The recordings were obtained using a high-speed digital imaging system. Three dimensional coordinates were computed for fleshpoints along the entire medial surface. The trajectories of the fleshpoints were preprocessed using the method of Empirical Eigenfunctions. RESULTS: Although considerable variability existed within the data, in general, the medial-lateral displacements and vertical displacements of the vocal fold fleshpoints were large compared with anterior-posterior displacements. For both normal and fry-like phonation, the largest displacements and velocities were concentrated in the upper medial portion. During normal phonation, the mucosal wave propagated primarily in a vertical direction. Above a certain threshold of subglottal pressure (or stimulation to the recurrent laryngeal nerve), an abrupt transition from chest-like to fry-like phonation was observed. CONCLUSIONS: The study reports unique, quantitative data regarding the medial surface dynamics of an in vivo canine vocal fold during phonation, capturing both chest-like and fry-like vibration patterns. These data quantify a complex set of dynamics. The mathematical modeling of such complexity is still in its infancy and requires quantitative data of this nature for development, validation, and testing.

Animals↗
PubMed1998

Dynamics of subneoglottic lumen in tracheoesophageal phonation.

The patient who employs tracheoesophageal (TE) phonation uses expiratory air passing through the TE fistula to vibrate the mucosa of the neoglottis located in the hypopharynx. To clarify the dynamics of the subneoglottic lumen during phonation, we performed fiberoptic endoscopy and fluoroscopy in 13 TE speakers. During phonation, fiberoptic endoscopy showed concentric closure of the esophagus with ballooning of the subneoglottic lumen, followed by opening of the esophagus during inspiration. Fluoroscopy revealed a dilated subneoglottic lumen and a closure of the esophagus at the bottom of the lumen during phonation. These findings provide evidence for a mechanism to protect against the influx of air deep into the esophagus during TE phonation. We conclude that during TE phonation, a closed airway is established from the lung to the neoglottis that enables the TE speaker to use expiratory air effectively for phonation.

Aged↗