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1.
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.  相似文献   

2.
Aerodynamic parameters provide objective and quantitative measures of laryngeal functional status. Jiang et al previously introduced an airflow interruption technique that can determine mean phonatory airflow, subglottic pressure, and phonation threshold pressure simultaneously and noninvasively. In this study, we performed receiver operating characteristic (ROC) analysis to evaluate this airflow interruption apparatus for voice profile analysis in subjects with laryngeal polyps or nodules or with Parkinson's disease. Patients with polyps (n = 14), nodules (n = 9), and Parkinson's disease (n = 12) were evaluated with the airflow interruption apparatus. Normal subjects served as controls. Mean airflow, subglottic pressure, and phonation threshold pressure were determined. Discriminant analysis was used to create linear equations combining all three parameters in order to obtain a new combined parameter. Solutions to the linear equations yielded values for the combined parameter that took into account mean airflow, subglottic pressure, and phonation threshold pressure. Combined parameter values were used as data to generate ROC curves. Laryngeal polyps were distinguished from the normal larynx with a sensitivity of 0.929 and a specificity of 0.933 at the point of maximal efficiency. The area under the ROC curve was 0.977 (Az). Patients with Parkinson's disease were distinguished from normal subjects with a sensitivity of 0.667 and a specificity of 0.909 at the point of maximal efficiency. The area under the ROC curve was 0.7958 (Az). Nodules were able to be distinguished from normal with a sensitivity of 0.889 and a specificity of 1.00. The area under the ROC curve was 0.9565 (Az). Our conclusions are twofold. First, aerodynamic parameters may be combined for simultaneous consideration by the construction of linear equations by means of discriminant analysis. Second, the airflow interruption apparatus, when used for voice function evaluation, has high sensitivity and specificity.  相似文献   

3.
Subglottal pressure (SGP) is a valuable parameter in the research and clinical assessment of laryngeal function. The lungs serve as a constant pressure source during sustained phonation, and that pressure, SGP, can be used to determine the efficiency with which the larynx converts aerodynamic power to acoustic power. As the larynx serves as an aerodynamic transducer, the vocal efficiency (Ve) coefficient, defined as acoustic power (dB) divided by aerodynamic power (SGP x glottal airflow) has been shown to reliably reflect vocal health. However, current SGP measurement techniques are hesitantly used because of either an invasive nature or the requirement of intensive patient training. This study tests a novel device that has been designed to noninvasively estimate SGP through mechanical airflow redirection, producing a numeric output on completion of the trial, which lasts only a few seconds. The novelty of this design lies in the ease of use for both the patient and the clinician. Multiple mechanical airflow redirections occlude the airway for only 135 ms, which is predicted to limit the effect of confounding laryngeal reflexes that may occur during the trials. Additionally, the airflow redirection into a retention device allows for the pneumatic in-trial comparison of the estimated SGP with the pressure achieved by the patient, providing a numeric output to the clinician on completion.  相似文献   

4.
空气动力学在测试呼吸与发声关系中的临床应用   总被引:9,自引:5,他引:4  
目的 研究正常人呼吸与发声关系。测定正常人的各项空气动力学指标,以期建立一种无创伤性的噪音检查方法,能够对噪音功能做出正确的评估。方法 应用空气动力学方法,使用噪音功能分析仪(Aeropone Ⅱ Model 6800)和可视音调仪(Visipitch6097),先记录下受试者的肺活量,再嘱受试者在自然舒适的音调和声音强度下,尽可能地发元音/a:/,同时记录最长发声时间、平均气流率、平均音调、声音  相似文献   

5.
Vocal efficiency is a quantitative measure of the ability of the larynx to convert subglottal power to acoustic power. On the basis of the scant previous literature and clinical intuition, we tested the hypothesis that vocal efficiency, as an indicator of the functional status of the larynx, is abnormally reduced in persons with vocal nodules and polyps. Because the most difficult aspect of obtaining measures of vocal efficiency has been the determination of subglottal pressure, we applied a noninvasive airflow interruption technique for this purpose. Subjects with normal voices (n = 22), vocal polyps (n = 14), and vocal nodules (n = 16) phonated at different intensities into a mask connected by way of piping to a flow meter, a pressure transducer, and an acoustic microphone. Inflation of a balloon-type valve located within the piping provided interruption of phonation. The intraoral pressure plateau occurring during flow interruption was used to estimate subglottal pressure. Subglottal power and acoustic power were determined, and their quotient provided a measure of vocal efficiency. The vocal efficiency in the normal subjects averaged 1.15 x 10(-5) at 70 dB, 3.17 x 10(-5) at 75 dB, 7.52 x 10(-5) at 80 dB, and 1.41 x 10(-4) at 85 dB. The vocal efficiency in the patients with vocal polyps averaged 3.62 x 10(-6) at 70 dB, 8.34 x 10(-6) at 75 dB, 2.10 x 10(-5) at 80 dB, and 4.26 x 10(-5) at 85 dB. The vocal efficiency in the patients with vocal nodules averaged 4.32 x 10(-6) at 70 dB, 1.57 x 10(-5) at 75 dB, 4.26 x 10(-5) at 80 dB, and 8.34 x 10(-5) at 85 dB. As compared to the normal subjects, the patients with laryngeal polyps or vocal nodules had significantly reduced vocal efficiency. These results provide quantitative verification of the clinical impression of inefficient phonation in patients with mass lesions of the vocal folds.  相似文献   

6.
OBJECTIVE: We used multi-slice helical computerized tomography (MSHCT) to evaluate the 3D characteristics of the laryngeal structures in patients with unilateral vocal fold paralysis (UVFP) during phonation, and compared the results with those obtained using an aerodynamic vocal function test. MATERIAL AND METHODS: The subjects were 37 patients with UVFP. The region over the larynx was scanned during quiet phonation and again during inspiration using MSHCT, and 3D endoscopic and coronal reconstruction images were produced. Maximum phonation time (MPT) and mean airflow rate (MFR) during phonation were measured. RESULTS: During phonation, the affected fold was thinner than the healthy fold in 30 subjects and located at a higher position than the healthy fold in 21 subjects. Abduction or thinning of the affected fold during phonation (paradoxical movement) was seen in seven subjects. MFR was significantly greater when the affected fold was thinner than the healthy fold during phonation, and MPT was significantly shorter when the affected fold showed paradoxical movement. Over-adduction of the healthy fold during phonation was present in 15 subjects. There were no significant differences in MPT or MFR between subjects with and without over-adduction. CONCLUSION: The combination of MSHCT endoscopic and coronal reconstruction images enables the 3D characteristics of the unilaterally paralyzed larynx to be visualized during phonation, and some of these characteristics are significantly correlated with vocal function in patients with UVFP.  相似文献   

7.
The voice obtained with the Staffieri method of surgical voice rehabilitation after total laryngectomy was studied in 20 subjects and objectively described in terms of selected acoustic and aerodynamic parameters. Intensity and frequency, pressure and airflow were studied during sustained phonation of the vowel 'a'. Simultaneous recordings showed a relationship between intensity and between fundamental frequency, pressure and airflow in most of the subjects. As the subjects in the present study were not able to produce a vowel at target intensities and frequencies, the data were interpolated to 65 dB (A) intensity level for comparison purposes. We found no indication that from an acoustical and aerodynamical point of view, the Staffieri procedure should be preferred over other alaryngeal voice production methods.  相似文献   

8.
BACKGROUND: Tracheostoma valves are used to make hand-free speaking possible for persons who have undergone a laryngectomy. OBJECTIVE: To design and test a new tracheostoma valve to improve existing tracheostoma valves. METHODS: The tracheostoma valve closes by means of strong inhalation so that all the air that is exhaled is available for phonation. The device automatically stays in the"speaking position" until the patient deliberately changes the device to the "breathing position" by a fast expiration. If all the air that has been exhaled has been consumed during phonation, the patient can inhale again, without changing the device, because a small valve automatically opens, thus allowing phonation without time limits. An experimental setup with a computer-based acquisition program was used to measure the pressure at which the valve opened and the flow at which the valve closed. The pressure and flow needed to open and close the magnetic adjustable valve were measured for different positions and contained in the computer through a data acquisition program. Also, the airflow resistance coefficients for inhaling and exhaling were measured. RESULTS: The airflow necessary to close the tracheostoma valve ranges from 1.6 to 3.8 L/s. The opening pressure of the valve ranges from 1 to 7 kPa. The airflow resistance coefficient is 290 Pa x s2 x L(-2) for inhalation and 430 Pa x s(2) x L(-2) for exhalation. CONCLUSIONS: The device appears to function well in physiological ranges and is optimally adjustable. The airflow resistance coefficient lies in the range of the entire airway resistance (120-470 Pa x s(2) x L(-2)) in quiet breathing.  相似文献   

9.
P Cole  T Havas 《Rhinology》1987,25(3):159-166
Nasal airflow resistances were measured simultaneously by face mask and "head-out" body plethysmograph and compared. Computer averaging of transnasal pressure and flow signals digitized at 50Hz during 5 breath sequences was employed to determine a ratio of pressure to flow as an index of nasal resistance to breathing. The mean value of ten plethysmograph measurements differed by only 2.0% from that of ten face mask measurements which were made simultaneously. Coefficients of variation of plethysmograph resistance measurements averaged less than 6% in twenty subjects (ten measurements/subject) aged 7-68 years over an intersubject resistance range of 1 to 7 cms H2O/l/sec (0.1-0.7 Pa/cm3/sec). Voluntarily altered minute ventilations from 8-28 l/min in a subject at rest increased this variation to 10%. The "head-out" body plethysmograph is a versatile and reliable instrument for assessment of nasal respiratory airflow resistance.  相似文献   

10.
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.  相似文献   

11.
The source-filter theory of speech production describes a glottal energy source (volume velocity waveform) that is filtered by the vocal tract and radiates from the mouth as phonation. The characteristics of the volume velocity waveform, the source that drives phonation, have been estimated, but never directly measured at the glottis. To accomplish this measurement, constant temperature anemometer probes were used in an in vivo canine constant pressure model of phonation. A 3-probe array was positioned supraglottically, and an endoscopic camera was positioned subglottically. Simultaneous recordings of airflow velocity (using anemometry) and glottal area (using stroboscopy) were made in 3 animals. Glottal airflow velocities and areas were combined to produce direct measurements of glottal volume velocity waveforms. The anterior and middle parts of the glottis contributed significantly to the volume velocity waveform, with less contribution from the posterior part of the glottis. The measured volume velocity waveforms were successfully fitted to a well-known laryngeal airflow model. A noninvasive measured volume velocity waveform holds promise for future clinical use.  相似文献   

12.
对10例(20个声样)26-45岁健康人分别以胸声及假声发持续性元音“i”及重复性章节“Pi”进行了纤维喉镜及气流动力学检查。结果表明:(1)假地声门闭合程度较胸声明显降低;(2)假声时气流率罗胸声时高,这与假声门闭合降低有关;(3)当胸声转为假声时,口腔压力升高,这可能与增加声带张力及维持声带振动频率有关。  相似文献   

13.
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.  相似文献   

14.
Hottinger DG  Tao C  Jiang JJ 《The Laryngoscope》2007,117(9):1695-1699
OBJECTIVES/HYPOTHESIS: This experiment studied a new aerodynamic parameter, phonation threshold flow, along with phonation threshold pressure, by varying prephonatory glottal width in canine larynges ex vivo. Goals were to examine phonation threshold flow as a measurable parameter sensitive to physiologic changes in the vocal folds and compare the relative sensitivities of phonation threshold flow and phonation threshold pressure. METHODS: Ten excised canine larynges were tested on a bench apparatus for subglottal pressure and airflow at phonation onset. Metal shims simulated abduction levels ranging from 0.0 to 4.0 mm. For each glottal configuration, airflow through the larynx was increased until the vocal folds began vibrating, and onset airflow and pressures were recorded. RESULTS: One-way analysis of variance (ANOVA) found significant differences in the aggregate phonation threshold flow means over the latter portion of the width domain (1.0-4.0 mm). Phonation threshold flow increased as posterior glottal width increased and was modeled linearly. One-way ANOVA of phonation threshold pressure means was insignificant, with a P value of .941. CONCLUSION: Results showed phonation threshold flow to be more sensitive to posterior glottal width changes than phonation threshold pressure. Therefore, phonation threshold flow could be a more effective indicator than phonation threshold pressure for those vocal diseases related to abduction.  相似文献   

15.
《Acta oto-laryngologica》2012,132(2):274-277
Objective—We used multi-slice helical computerized tomography (MSHCT) to evaluate the 3D characteristics of the laryngeal structures in patients with unilateral vocal fold paralysis (UVFP) during phonation, and compared the results with those obtained using an aerodynamic vocal function test. Material and methods—The subjects were 37 patients with UVFP. The region over the larynx was scanned during quiet phonation and again during inspiration using MSHCT, and 3D endoscopic and coronal reconstruction images were produced. Maximum phonation time (MPT) and mean airflow rate (MFR) during phonation were measured. Results—During phonation, the affected fold was thinner than the healthy fold in 30 subjects and located at a higher position than the healthy fold in 21 subjects. Abduction or thinning of the affected fold during phonation (paradoxical movement) was seen in seven subjects. MFR was significantly greater when the affected fold was thinner than the healthy fold during phonation, and MPT was significantly shorter when the affected fold showed paradoxical movement. Over-adduction of the healthy fold during phonation was present in 15 subjects. There were no significant differences in MPT or MFR between subjects with and without over-adduction. Conclusion—The combination of MSHCT endoscopic and coronal reconstruction images enables the 3D characteristics of the unilaterally paralyzed larynx to be visualized during phonation, and some of these characteristics are significantly correlated with vocal function in patients with UVFP.  相似文献   

16.
Regner MF  Tao C  Zhuang P  Jiang JJ 《The Laryngoscope》2008,118(7):1313-1317
Objectives/Hypothesis: In this study, we examined the hypothesis that the minimum flow required for phonation onset, the onset phonation threshold flow (PTF), is greater than the minimum flow to sustain phonation, the offset PTF. We also explored the hypothesis that the ratio of these two (PTF offset divided by PTF onset) falls within [0.707, 1.0]. Study Design: This was a methodology study to measure onset and offset PTFs in 10 excised canine larynges; their ratio (PTF offset divided by PTF onset) was predicted to fall in a specific domain. Methods: The onset and offset PTF and phonation threshold pressure (PTP) values were observed using 10 excised canine larynges mounted on a bench apparatus. The subglottal flow was increased until phonation was observed, and then decreased until phonation ceased; airflow and pressure measurements at critical conditions of phonation were observed as the PTF and PTP. Larynges with elongated vocal folds were then tested to observe PTF and determine if the hypothesis was observed in pathologic‐like larynges. Results: The offset PTF was always less than the onset PTF (P ? .0001) and 80.0% of the observed onset‐offset PTF ratios were bound by [0.707, 1.0]. Conclusions: PTF onset or offset could be a useful diagnostic parameter of the voice, particularly when used in conjunction with PTP to describe laryngeal resistance and aerodynamic power. Further exploration of the relationship between onset and offset PTF values could augment clinical diagnostic ability and advance current theories on the physics of phonation.  相似文献   

17.
Relevance of subglottic pressure in normal and dysphonic subjects   总被引:1,自引:0,他引:1  
The purpose of this study was to determine the clinical value of subglottic pressure (SGP) in normal and dysphonic subjects. “The airway interrupted method” was used to measure the intra-oral pressure. Voice samples from 60 healthy subjects and 79 dysphonic patients were recorded under normal conditions of pitch and intensity. In normal subjects, age and gender have no significant impact on mean and peak SGP. The peak SGP measurements are significantly higher in dysphonic patients and could be included in the basic clinical set of objective voice parameters. No differences could be shown between pre- and postoperative assessments or between groups of dysphonic patients.  相似文献   

18.
Temporal and respiratory responses to a loss of velar resistance were measured in 107 subjects demonstrating varying degrees of velopharyngeal inadequacy. The subject data were compared to data generated by a mechanical model representing a passive system. The pressure-flow technique was used to estimate velopharyngeal orifice size and measure respiratory and temporal characteristics of aerodynamic events associated with the production of the nasal-plosive blend /mp/ in the word "hamper". Subjects were categorized as having adequate closure (less than 0.05 cm2), adequate/borderline closure (0.05-0.09 cm2), borderline/inadequate closure (0.10-0.19 cm2) and inadequate closure (greater than or equal to 0.20 cm2). The data revealed that intraoral pressure fell 10-fold in the model as velopharyngeal orifice area changed from adequate closure to inadequate. The subject data demonstrated only a 1.4-fold drop in pressure. Airflow data indicated that there was a 10-fold increase in respiratory volume in the subject data corresponding to the change from adequacy to inadequacy. When respiratory and temporal responses were assessed together, the findings revealed that airflow and temporal changes minimized the fall of pressure as velar resistance declined across groups.  相似文献   

19.
Acoustic spectral analysis has been used to describe voice tremor with some success, but no feature distinguishing pathological from normal tremor has been clearly identified. To assist in monitoring voice tremor associated with neurological diseases, objective and quantifiable measures that can distinguish between normal and pathological tremor are desired. This study explored the plausibility of using airflow and acoustic signals to quantify the frequency and amplitude of voice tremor and potentially to distinguish pathological from normal tremor. Subjects were 10 individuals with pathological tremor, most of them individuals with Parkinson's disease, and 10 gender and age-matched individuals with no voice disorder. Simultaneous acoustic and airflow signals were recorded during sustained vowel phonation. The acoustic intensity contours and the airflow signals were submitted to spectral analysis. A peak prominence ratio, defined as the ratio of the spectral peak energy to the overall signal energy, was calculated for each spectral peak below 30 Hz. For each subject, the 6 spectral peaks with the highest peak prominence ratios were selected. Frequency values of the 6 selected acoustic or airflow spectral peaks failed to distinguish tremor group from control group. Peak prominence ratios of the 6 selected acoustic spectral peaks were significantly higher for tremor group than for control group. Although spectral analysis of airflow signals was not useful in differentiating tremor group from control group, acoustic intensity contours and airflow time waveforms were highly and positively correlated in more tremor subjects (90%) than control subjects (40%). This finding suggests that the relationship between acoustic intensity contours and airflow time waveforms may reflect the presence and the source of voice tremor.  相似文献   

20.
OBJECTIVES: The purpose of this study was to determine whether stability of airflow, as well as mean airflow, increased following botulinum toxin injection to laryngeal and extralaryngeal muscles in persons with spasmodic dysphonia (SD), some with associated vocal tremor (VT). STUDY DESIGN: Aerodynamic data were collected from five subjects before and at 2, 4, and 8 weeks after they received treatment by each of two different arms in an injection protocol in a crossover study. One arm of the protocol involved treatment of the thyroarytenoid muscles only. The other arm involved treatment of both the thyroarytenoid muscles and the strap muscles. METHODS: Measures of mean airflow and coefficient of variation (COV) of airflow during phonation were obtained. A decrease in the COV of airflow would indicate increased stability of phonatory airflow. RESULTS: Before treatment, all subjects with SD/VT exhibited mean airflows that were similar to controls. The COV of airflow ranged from normal to substantially elevated. Following botulinum injection, mean airflow characteristically increased and COV of airflow decreased. CONCLUSIONS: This finding suggests there is a change in the type, as well as the level, of activity in the muscles of speech production following botulinum toxin injection. The increase in airflow stability identified could be due to increased stability of the laryngeal system and possibly of the respiratory system as well.  相似文献   

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