Comfortable Phonation Research Articles

Effects of Liuzijue Qigong Posture on Aerodynamics of Phonation in Healthy Volunteers

To verify the possible function of Liuzijue Qigong (LQG), a kind of traditional Chinese health exercise, in improving phonation. A total of 30 healthy volunteers (10 males, 20 females) without voice disorders were included. The subjects were asked to have phonation tasks at the sitting and LQG postures. Aerodynamic, electroglottographic, and acoustic parameters were measured. Expiratory Volume (FVC); Subglottic Pressure at comfortable phonation (SGP), Glottal Resistance (GR), Glottal Efficiency (GE); Contact Quotient (CQ), Mean Flow (MF), Fundamental frequency (F0), Mean Sound Pressure Level (SPL); Phonation Threshold Pressure (PTP); and Maximum Phonation Time (MPT) were measured and analyzed. In total subjects, the analysis showed a significant increase in FVC (P = 0.020), SGP (P = 0.043), F0 (P = 0.021), and PTP (P = 0.000) at the LQG posture when compared with the sitting posture, and there is no difference in CQ, MF, SPL, GR, GE, and MPT. The results showed LQG posture increased the respiratory support and glottal closure, while induced the respiratory system and vocal system in coordination to improve phonation. It is logical to postulate that LQG has potential in the management of voice disorders with glottal closure insufficiency.

The Normative Study of Acoustic and Aerodynamic Characteristics of Voice among Healthy Adult Turkish Speaker Population.

Phonatory Aerodynamic System (PAS Model 6600) is an evaluation instrument that assesses the effectiveness of surgical interventions, treatments, and therapy for voice disorders. It can be used for the assessment of voice disorders by supporting other perceptual and instrumental methods. It is important to establish normative data, because the use of appropriate norms is necessary for diagnostic and descriptive accuracy. Therefore, this study is aimed primarily at establishing adult normative databases for phonatory aerodynamic measures obtained with the KayPENTAX PAS Model 6600 among healthy adult Turkish speakers and then examining the effect of age, gender, and age-gender interaction variables on these measures. The contribution of the study is considered so important since it will generate normative data for all measurements—except the mean pitch—by the five protocols of PAS for the first time. Two hundred and six healthy Turkish speakers with normal voice (106 women and 100 men) were included in the study and stratified into three age groups. Forty-five phonatory aerodynamic measures across five PAS protocols (vital capacity, maximum sustained phonation, comfortable sustained phonation, variation in sound pressure level, and voicing efficiency) were collected. Age, gender, and age-gender interaction variables were analyzed for 45 PAS parameters. Significant gender and age effect was found for 30 and 19 variables, respectively. Gender-age interaction together was observed for only 6 parameters. Significant differences were not found for the remaining 10 parameters. Significant age and gender effects were observed for 35 phonatory and aerodynamic measures which are essential part of the objective clinical assessment of voice. Consequently, normative data used as reference in voice assessment should be generated according to age and gender differences.

Comparison of Aerodynamic Characteristics During Reading Paragraph Tasks in Normal Male and Female Adults

Purpose: The present study was performed to compare the aerodynamic characteristics of males and females during reading paragraph task.Methods: Thirty-seven normal adult males (18-30 yrs) and thirty-nine normal adult females (18-34 yrs) were participated in this experiment. They read a part of ‘Gaeul’ paragraph with comfortable phonation, and the reading samples were recorded and analyzed by ‘Running Speech’ program of Phonatory Aerodynamic System (PAS).Results: Phonation time (with voicing) and expiratory airflow duration were significantly longer in females, but measures of inspiratory airflow duration, peak expiratory airflow, expiratory and inspiratory volumes were significantly higher in males. The difference in total duration and peak inspiratory airflow did not show statistical significance.Conclusion: Results revealed that there was a significant gender difference in aerodynamic measures of duration and airflow during the reading paragraph task. In evaluating and intervening aerodynamics of voice and voice disorder patients, we should also consider the gender-different aerodynamic characteristics in continuous speech.

Outcomes of voice therapy in children with benign vocal fold lesions

ObjectiveThis study aims to examine the effect of voice therapy on dysphonia on children with benign vocal fold lesions, as measured by perceptual evaluation using the Consensus Auditory Perceptual Evaluation of Voice (CAPE-V) and acoustic and aerodynamic measures (jitter, shimmer, noise-to-harmonic ratio, phonation threshold pressure, mean airflow during voicing, subglottic pressure during comfortable phonation). Study designProspective disease-specific outcomes database. MethodsSubjects identified in the database consisted of 28 children (14 male, 14 female) between the ages of three and eighteen. Pre- and post-therapy perceptual, acoustic and aerodynamic measures were compared using two-sided paired t-test. ResultsThere was a statistically significant difference in perceptual ratings of voice quality (p < .001) and in phonation threshold pressure before and after therapy (p = .034). While acoustic measures improved after therapy, changes were not statistically significant. ConclusionsChildren with dysphonia secondary to benign vocal fold lesions showed positive change in perceptual ratings of voice quality and in phonation threshold pressure after voice therapy.

Revisiting Sustained Phonation Time of /s/, /z/, and /α/

Research studies of maximum phonation time, have questioned its validity and value as a tool to assess laryngeal competence. This study proposes a fresh look at phonation time, from a different perspective. The interrelationships of the durations between semiocclusion vs. open vocal tract (/s/-/z/ vs. /α/) and voiced vs voiceless (/z/-/α/ vs. /s/) sound are examined to determine whether this approach might provide additional clinical insight into the respiratory phonatory efficiency of patients. Comfortable sustained phonation time of /s/, /z/ and /α/ was collected as part of the voice evaluation of patients referred by laryngologists for voice therapy. Inclusionary criteria: male and female subjects 19 years of age or older. Exclusionary criteria: autoimmune disorders, malignancies, major pulmonary/respiratory disorders. A total of 218 patients (150 females and 68 males) mean age of 53.6 met all the criteria. Means, standard deviations and t test were conducted to determine whether significant differences existed. t test results indicate significance between s/z P=0.002 and z/α P=0.004 for females but only slight significance in s/α P=0.03 for males. Close analysis of individual results observed four (4) different conditions or effects of fricative/semiocclusion and voicing: the close durations of the /s/ and /z/ relative to the /α/; the /z/ and /α/ are close in duration relative to the /s/; the spread of more than 5 seconds between /s/, /z/ and /α/ relative to the others; and similar duration of /s/, /z/, and /α/. Significant differences exist in the durations of comfortable phonation time of sustained /s/ and /z/ and /α/ thought to be related to effects of semiocclusion, fricative consonants, and voicing. Phonation time should be seen not only in terms of duration, but the interplay of the phonemic qualities of the sounds as they relate of laryngeal efficiency.

Electroglottography in the diagnosis of functional dysphonia

IntroductionElectroglottography (EGG) is the most commonly used method of indirect visual examination of vocal fold vibration.AimThe study was conducted with an aim of assessing EGG quasi open quotient (QOQEGG) in different functional dysphonias to develop a differential diagnosis. The second aim was to check the influence of articulation on QOQEGG values.Material and methodsThere were 20 people without voice problems, 20 patients with hypofunctional dysphonia and 20 patients with hyperfunctional dysphonia included in the study. Electroglottography was recorded during comfortable sustained phonation of [a], [e], [i], [o], [u].ResultsThere were no statistically significant differences in QOQEGG observed during phonation of different vowels in the control group and patients with hyperfunctional dysphonia. In patients with hypofunctional dysphonia, significantly higher values of QOQEGG were observed during [a] and [e]. Both in the control and in studied groups vowel [i] was vocalized significantly quieter.ConclusionsTo conclude, EGG can be useful in differential diagnosis of functional dysphonia. QOQEGG is a parameter differentiating hypofunctional dysphonia from hyperfunctional dysphonia. Dissimilarities in articulation of different vowels in patients with various types of dysphonia influence values of QOQEGG. EGG study protocol in cases of functional dysphonia should include a comparison of [a], [e], [i] vowels.

Brain activity during phonation in healthy female singers with supraglottic compression: an fMRI pilot study

This pilot study evaluated the usability of functional magnetic resonance imaging (fMRI) to detect brain activation during phonation in healthy female singers with supraglottic compression. Four healthy female classical singers (mean age: 26 years) participated in the study. All subjects had normal vocal folds and vocal characteristics and showed supraglottic compression. The fMRI experiment was carried out using a block design paradigm. Brain activation during phonation and exhalation was analyzed using Brain Voyager software (Brain Innovation B.V., Maastricht, The Netherlands). An fMRI data analysis showed a significant effect of phonation control in the bilateral pre/postcentral gyrus, and in the frontal, cingulate, superior and middle temporal gyrus, as well as in the parietal lobe, insula, lingual gyrus, cerebellum, thalamus and brainstem. These activation areas are consistent with previous reports using other fMRI protocols. In addition, a significant effect of phonation compared to exhalation control was found in the bilateral superior temporal gyrus, and the pre/postcentral gyrus. This fMRI pilot study allowed to detect a normal pattern of brain activity during phonation in healthy female singers with supraglottic compression using the proposed protocol. However, the pilot study detected problems with the experimental material/procedures that would necessitate refining the fMRI protocol. The phonation tasks were not capable to show brain activation difference between high-pitched and comfortable phonation. Further fMRI studies manipulating vocal parameters during phonation of the vowels /a/ and /i/ may elicit more distinctive hemodynamic response (HDR) activity patterns relative to voice modulation.

Acoustic Perturbation Measures Improve with Increasing Vocal Intensity in Individuals With and Without Voice Disorders

In vocally healthy children and adults, speaking voice loudness differences can significantly confound acoustic perturbation measurements. This study examines the effects of voice sound pressure level (SPL) on jitter, shimmer, and harmonics-to-noise ratio (HNR) in adults with voice disorders and a control group with normal vocal status. This is a matched case-control study. We assessed 58 adult female voice patients matched according to approximate age and occupation with 58 vocally healthy women. Diagnoses included vocal fold nodules (n = 39, 67.2%), polyps (n = 5, 8.6%), and muscle tension dysphonia (n = 14, 24.1%). All participants sustained the vowel /a/ at soft, comfortable, and loud phonation levels. Acoustic voice SPL, jitter, shimmer, and HNR were computed using Praat. The effects of loudness condition, voice SPL, pathology, differential diagnosis, age, and professional voice use level on acoustic perturbation measures were assessed using linear mixed models and Wilcoxon signed rank tests. In both patient and normative control groups, increasing voice SPL correlated significantly (P < 0.001) with decreased jitter and shimmer, and increased HNR. Voice pathology and differential diagnosis were not linked to systematically higher jitter and shimmer. HNR levels, however, were statistically higher in the patient group than in the control group at comfortable phonation levels. Professional voice use level had a significant effect (P < 0.05) on jitter, shimmer, and HNR. The clinical value of acoustic jitter, shimmer, and HNR may be limited if speaking voice SPL and professional voice use level effects are not controlled for. Future studies are warranted to investigate whether perturbation measures are useful clinical outcome metrics when controlling for these effects.

Functional Magnetic Resonance Imaging Study of Brain Activity Associated With Pitch Adaptation During Phonation in Healthy Women Without Voice Disorders

This functional magnetic resonance imaging (fMRI) study investigated the brain activity associated with pitch adaptation during phonation in healthy women without voice disorders. This is an interventional prospective study. Sixteen healthy women (mean age: 24.3 years) participated in a blocked design fMRI experiment involving two phonation (comfortable phonation and high-pitched phonation) and exhalation (prolonged exhalation) tasks. BrainVoyager QX Version 2.4 software was used for group-level general linear model analysis (q[FDR] < 0.05). Analyses showed a significant main effect of phonation with pitch adaptation compared with rest period in the bilateral precentral gyrus, superior frontal gyrus, posterior cingulate gyrus, superior and middle temporal gyrus, insula and cerebellum, left middle and inferior frontal gyrus, right lingual gyrus, cingulate gyrus, and thalamus. Statistical results also identified a significant main effect of exhalation compared with rest period in the bilateral precentral gyrus, cerebellum, right lingual gyrus, thalamus, and left supramarginal gyrus. In addition, a significant main effect of phonation was found in the bilateral superior temporal gyrus and right insula, as well as in the left midbrain periaqueductal gray for high-pitched phonation only. We demonstrated that a blocked design fMRI is sensitive enough to define a widespread network of activation associated with phonation involving pitch variation. The results of this study will be implemented in our future research on phonation and its disorders.

Survey of Voice Acoustic Parameters in Iranian Female Teachers

SummaryObjectivesTeachers are one of the professional voice users. Voice problems are common among them. Female teachers are known to have more voice problems than male ones. Furthermore, there are only few studies on the voice of Iranian female teachers. The present study investigated the acoustic parameters of voice in Iranian female teachers and compares them with nonteachers.MethodsIn this cross-sectional study, 90 Iranian female elementary teachers, 30–50 years old, and 90 Iranian female nonteachers in the same age were assessed between May 2010 and October 2011. Data collection was carried out, using the Dr. Speech software (subprogram: vocal assessment Version 4.0 from Tiger Electronics) at the speech therapy clinic under a comfortable phonation. Normal voice in practitioners was judged by the perceptual evaluation by a voice therapist and indirect laryngoscopy examination by an otorhinolaryngologist. Voice characteristics were assessed with GRBAS scale. The speech sample was sustained /â/ using habitual and constant vocal for 10 seconds. Three tokens from each subject were obtained. Then, each subject was asked to read a standard passage in Farsi. Eventually, the difference measures of F0, jitter, shimmer, harmonic to noise ratio (HNR), and maximum of phonation time (MPT) between two groups were investigated by statistics software SPSS 19.0 (IBM corp.2010).ResultsResults showed that the values of F0 were higher in teachers (210.03 Hz) than in nonteachers (194.11 Hz; P < 0.001). In addition, the values of perturbation measures were greater in teachers (jitter 0.32% and shimmer 4.63%) than those in the control group (jitter 0.22% and shimmer 3.15%; P < 0.001), but in HNR and MPT values, nonteachers showed higher levels (P < 0.001). The value of HNR in teachers was (18.84±1.56) but it was (21.3±1.73) in non-teachers and MPT value in teachers was (16.83±3.65) and in non-teachers was (22.5±5.2).ConclusionsIt can be concluded that vocal overuse, abuse, or misuse during teaching over a period of time result in achievement of inadequate phonatory pattern with excessive musculoskeletal tension, and the possible result is tissue changes in teacher's voice. In addition, acoustic analysis of voice parameters for teachers may significantly contribute to the objective voice examination of this group.

Acoustic characteristics of different target vowels during the laryngeal telescopy

The aim of this study was to investigate the acoustic characteristics of target vowels phonated in normal voice persons while performing laryngeal telescopy. The acoustic characteristics are compared to show the extent of possible difference to speculate their impact on phonation function. Thirty-four male subjects aged 20-39 years with normal voice were included in this study. The target vowels were /i/ and /ɛ/. Recording of voice samples was done under natural phonation and during laryngeal telescopy. The acoustic analysis included the parameters of fundamental frequency, jitter, shimmer and noise-to-harmonic ratio. The sound of a target vowel /ɛ/ was perceived identical in more than 90% of the subjects by the examiner and speech language pathologist during the telescopy. Both /i/ and /ɛ/ sounds showed significant difference when compared with the results under natural phonation. There was no significant difference between /i/ and /ɛ/ during the telescopy. The present study showed that change in target vowels during laryngeal telescopy makes no significant difference in the acoustic characteristics. The results may lead to the speculation that the phonation mechanism was not affected significantly by different vowels during the telescopy. This study may suggest that in the principle of comfortable phonation, introduction of the target vowels /i/ and /ɛ/ is practical.

Electroglottographic Study of Seven Semi-Occluded Exercises: LaxVox, Straw, Lip-Trill, Tongue-Trill, Humming, Hand-Over-Mouth, and Tongue-Trill Combined With Hand-Over-Mouth

Semi-occluded vocal tract exercises (SOVTE) are often used in voice clinics. SOVTE change the acoustic vocal tract impedance in relation to the glottis impedance, improving voice quality. However, differences among SOVTE, such as the number of vibration sources into the vocal tract, are often disregarded by clinicians. Some SOVTE present single, whereas others double source. This study aims at investigating changes in voice production pattern for a series of SOVTE. A combined exercise (tongue-trill coupled with hand-over-mouth) was implemented to illustrate the effect of a secondary source of vibration in the vocal tract. Twenty-three healthy volunteers performed a series of SOVTE: LaxVox, straw, lip-trill, tongue-trill, hand-over-mouth, humming, and tongue-trill combined with hand-over-mouth. Comfortable phonation served as control exercise. The dependent variables were electroglottography contact quotient (CQ), contact quotient range (CQr), fundamental frequency (F0), fundamental frequency range, and difference between the first formant frequency and F0 (F1 - F0). A significant difference for CQr scores compared with comfortable phonation was found for the combined tongue-trill with hand-over-mouth, lip-trill, LaxVox, and tongue-trill exercises. The F1 - F0 acoustic analysis showed significant differences in scores for exercises with one versus two sources of vibration. The results indicate that SOVTE should be divided into two groups, as follows: (a) steady (single sourced) with lower CQr and F1 - F0 difference (hand-over-mouth, humming, and straw) and (b) fluctuating (dual source) with larger CQr and F1 - F0 difference (tongue-trill, lip-trill, and LaxVox). Because of these differences, also different therapeutic effects can be expected. Tongue-trill combined with hand-over-mouth exhibited mixed effects of both the exercise groups.

Analysis of High-Pitched Phonation Using Three-Dimensional Computed Tomography

Our aim was to use three-dimensional computed tomography (3DCT) to examine arytenoid cartilage movement during a high-pitched tone task. This was a prospective study. This study included 14 patients with male-to-female gender identity disorder who had undergone 3DCT imaging for surgical simulation between January 2007 and May 2008. First, to prove that the phonation condition was indeed one of the high-pitched phonation, we confirmed the rotational movement of the thyroid cartilage, horizontal gliding movement of the inferior horn, and vocal fold elongation on a high-pitched tone task. Next, we detected the arytenoid cartilage positions of the joint during a comparison of comfortable and high-pitched phonations. We measured the movement direction and movement distance of the arytenoid cartilage. In all cases, the cricothyroid space became narrower (rotation movement), and we observed anterior gliding movement of the inferior horn. In all cases, elongation of the vocal folds by the high-pitched phonation was confirmed and the arytenoid cartilages were displaced both anteriorly and caudally from the position during comfortable phonation by the high-pitched tone task. The arytenoid cartilages did not move posteriorly to elongate the vocal folds during high-pitched phonation. The arytenoid cartilages were pulled anteriorly and moved caudally because of tension associated with vocal fold elongation because of the task of high-pitched phonation. These results suggest that there are no movements at the cricoarytenoid joint that directly control the length of the vocal folds in accordance with pitch.

Determination of Fundamental Frequency and Voice Intensity in Iranian Men and Women Aged Between 18 and 45 Years

Acoustic measurements have become an essential aspect of voice assessment during the last few decades, and studies have established that normative data is necessary for acoustic analysis. In this study, two aspects of voice are reviewed. These two factors are fundamental frequency and intensity. This study was designed to establish the normal acoustic analysis parameters in normal Iranian adults. In this cross-sectional study, 200 healthy randomly selected subjects (100 men and 100 women) were assessed. Data collection was carried out using the Studio Speech software and Laryngograph processor (Laryngograph Ltd, London, UK), type: PCLX at the Larynx and Voice Disorders Clinic of Rasoul-e-Akram Hospital under comfortable phonation. The value of fundamental frequency in reading was greater for women (170-240 Hz) than for men (107-140 Hz). Also, the value of intensity was greater for women (73.54-84.99 dB) than for men (72.40-86.03 dB). The present study developed the normal data for fundamental frequency and intensity in Iranian speakers aged between 18 and 45 years. We concluded, fundamental frequency has significant differences between men and women, but intensity has no significant difference between them.

Clinical analysis of presbylarynx—Vocal fold atrophy in elderly individuals

Objective The proportion of elderly Japanese is increasing significantly and aging society greatly influences the medical services. The number of elderly patients who visited out Voice Outpatient Clinic has been increasing in recent years. The aim of the present study was to analyze the trend in the number of patients with aging-related vocal fold atrophy, and to assess the characteristics of senile change of vocal function. Methods A retrospective review of the 1999–2005 medical records of patients aged ≥65 years was conducted, and patients with presbylarynx were analyzed. We evaluated age, sex, occupation, maximal phonation time (MPT), and mean airflow rate (MFR) during comfortable phonation to assess the physiological characteristics of senile change of vocal function. We compared MFR of presbylarynx with those of normal elderly person. Results The number of patients aged ≥65 who visited our clinic in the 7-year study period was 361, and 72 (20%) were diagnosed with vocal fold atrophy. They included 47 (65%) men and 25 (35%) women, with a mean age of 71 years (range, 65–89). Among these patients, 27 (38%) were still employed at the time of consultation, while 17 (24%) were retired, at least 26 jobs required voice skills; and 15 patients (21%) were involved in singing and recitation of poems. MPT correlated negatively with age, while MFR correlated positively with age. Conclusion The number of elderly patient with vocal fold atrophy increased gradually almost every year. The male patients account for 65%. Thirty-three percent of patient of the present study with presbylarynx were still in the workforce. MFR correlated positively and significantly with age. MFR was higher in presbylarynx than normal elderly person.

Objective Voice Analysis of Iranian Speakers with Normal Voices

Objective measurements in general and acoustic measurements in particular have become a substantial aspect of voice assessment during the last few decades and studies have established that normative data is necessary for acoustic analysis. Voice acoustic analysis including fundamental frequency (F(0)), jitter, shimmer, harmonics-to-noise ratio (HNR), and maximum phonation time (MPT) can now be easily recorded and analyzed using a computer. Because these systems are widely used in clinical practice, this study was designed to establish the normal acoustic analysis parameters in normal Iranian adults. A group of 90 unpaid, healthy, randomly selected subjects with normal voices (45 Iranian men and 45 Iranian women), was selected for this study. Data collection was carried out, using the Dr. Speech Software (subprogram: vocal assessment version 4.0 from Tiger Electronics) at the speech therapy clinic under comfortable phonation. Each gender was separated equally into three age subgroups. Then differences between gender and age subgroups were investigated by statistics software SPSS 13.0. The value of (vowels /â/ and /i/) was greater for females (214.64+/-1.16; 228.06+/-1.5 Hz) than for males (112.82+/-0.94; 126.13+/-1.49 Hz). Conversely, the value of MPT was greater for males (26.30+/-1.29 s) than for females (18.56+/-0.88 s). There were no significant differences in average shimmer and jitter between females (1.21+/-0.03%; 0.22+/-0.01%) and males (1.22+/-0.02%; 0.23+/-0.02%). However, the value of HNR was greater for females (18.81+/-0.96 dB) than for males (18.42+/-0.57 dB). The present study developed a body of normal data for various parameters of acoustic analysis in different age groups and genders of normal Iranian adults. It seems that the majority of voice characteristics of adults was relatively stable and did not change with aging between 20 and 50 years. However, the voice characteristics of adults older than 50 years were not recorded in this study and therefore require further investigation.

Voice Production during a Weightlifting and Support Task

Although effort closure techniques have a long history in the treatment of hypofunctional and psychogenic voice disorders, there have been surprisingly few studies of their specific laryngeal and phonatory effects. The present study was designed to provide preliminary data on physiologic changes in voice production associated with a weightlifting and support maneuver. Twenty vocally healthy subjects (10 men and 10 women) lifted hand-held weights and steadily supported them with outstretched arms as they either sustained comfortable phonation or repeated the syllable /pi/. Both the male and female subjects showed an increase in the electroglottographic contact quotient, long-term F₀ variability, and estimated laryngeal airway resistance attributable to an elevated driving pressure. Conversely, there were no significant changes in mean F₀, pitch perturbation quotient (jitter), or phonatory airflow between the pre-lift and lift portions of their voice production, regardless of the amount of weight supported. The results of this study indicate that simultaneous phonation and weightlifting is associated with increased laryngeal airway resistance characterized by an elevation in driving pressure and medial compression of the vocal folds. Implications for an improved understanding of normal vocal physiology and for the therapeutic use of such air-trapping exercises are addressed.

Acoustic and perceptual analysis of modal and falsetto registers in females with dysphonia

Modal and falsetto registers are the basic vocal qualities used in female speaking voices. The purpose of this study was to identify the frequency at which modal register changed to falsetto register and the frequency range of each modal and falsetto register produced under three loudness levels: soft, comfortable and loud phonations in normal and dysphonic speakers. These data provide information on the relationship between vocal registers. It is hypothesized that vocal pathologies affect the frequency at which register change from one mode to another mode. Fifteen dysphonic and 15 non‐dysphonic females were assessed on their ability to produce tone series from the lowest to the highest frequency at soft, comfortable and loud phonations. Fourteen listeners served as judges to identify the first production of falsetto voice in each tone series. The first falsetto tone perceived was considered to represent the frequency at which the modal‐falsetto register change occurred perceptually. The change from modal to falsetto register in the tone series occurred between G4 (360.74 Hz) and B4 (485.23 Hz) in the dysphonic group and between A4 (421.00 Hz) and B4 (476.13 Hz) in the non‐dysphonic group among the three loudness levels. The results showed that the presence of dysphonia affected the production of vocal registers The dysphonic group demonstrated the modal‐falsetto register change at a significantly lower frequency and reduced frequency range in the modal register than those of the non‐dysphonic group in the soft and comfortable phonations. In producing falsetto register, the dysphonic group demonstrated reduced ability in producing falsetto register in soft and loud phonations when compared to the non‐dysphonic group. Physiological explanations are used to account for the observations.

Aerodynamic and Acoustic Parameters in CO2 Laser Posterior Transverse Cordotomy for Bilateral Vocal Fold Paralysis

The aim of this prospective study was to analyse airway improvement and acoustic and aerodynamic parameters after CO2 laser posterior transverse cordotomy (LPTC) in bilateral vocal fold paralysis (BVFP). Four patients (2 males, 2 females) were recorded pre- and post-operatively at 1, 3, 6, 12 and 24 months. Forced inspiratory volume during the first second (FIV), vital capacity, peakflow, and forced expiratory volume during the first second (FEV) were measured with the Gould II spirometer. Acoustic frequency features (average fundamental frequency, standard deviation, jitter, shimmer and harmonic-to-noise ratio) and speech duration parameters (maximum phonation time, number of words read per minute, and number of words per breath) were measured. Aerodynamic parameters were measured with the Aerophone II. Three tasks were completed. Pneumo-phonatory parameters in ?maximum sustained phonation? and in ?comfortable phonation?, and laryngeal aerodynamic parameters (intraoral air pressure, oral airflow and sound pressure level) were measured non-invasively. Glottal resistance and vocal efficiency were calculated. FIV increased significantly after LPTC (p=0.01). Postoperatively, frequency features were undetectable by standard commercialized algorithms. Acoustic and aerodynamic parameters improved in the measures obtained at the 6th postoperative month. These results were stable 2 years postoperatively in all cases. We conclude that laryngeal aerodynamic parameters can be used objectively to follow patients longitudinally after LPTC.

Examination of air usage during phonation: Correlations among test parameters

Summary Correlations among parameters indicating air usage during phonation were investigated in 60 normal subjects and 1,545 voice patients. The parameters examined were maximum phonation time (MPT), mean air flow rate for maximum sustained phonation (MFRm), mean air flow rate for comfortable phonation (MFRc), and phonation quotient (PQ). In normal subjects, correlations among MPT, MFRm, and PQ were high, but those between MFRc and the others were moderate. In cases of paralysis and hypofunctional dysphonia, all correlations between the four parameters were high. In the cases of polyp, nodule, epithelial hyperplasia, glottic carcinoma, and hyperfunctional dysphonia, the correlation between MPT and MFRc was moderate or not significant. The low correlation between these parameters was associated with the variations in flow rate differences between maximum and comfortable phonations. The results suggest that measurement of all four parameters is not necessary in routine tests and that MPT and MFRc should be measured in most voice patients.