Akihito Yamauchi

Evaluation of Vocal Fold Vibration With an Assessment Form for High-Speed Digital Imaging: Comparative Study between Healthy Young and Elderly Subjects

OBJECTIVES/STUDY DESIGN We conducted a prospective study with a subjective assessment form for high-speed digital imaging (HSDI) to elucidate the features of vocal fold vibrations in vocally healthy subjects and to clarify gender- and age-related differences. METHODS Healthy adult volunteers participated in this study. They were divided into young (aged 35 and younger) and elderly (aged 65 and older) groups, and the scores of an assessment form for HSDI characteristics elaborated at our institution were statistically analyzed. RESULTS Twenty-six young subjects (males: 9, females: 17; mean age: 27 years) and 20 elderly subjects (males: 8, females: 12; mean age: 72 years) were assigned to our study. Posterior gap and posterior-to-anterior longitudinal phase difference were characteristic to young females, whereas in young males, mucosal wave, anterior-to-posterior longitudinal phase difference, and supraglottic hyperactivity were frequent. In elderly males, axis shift, asymmetry, supraglottic hyperactivity, increased mucosal wave, lateral phase difference, and anterior-to-posterior longitudinal phase difference were frequent; and in elderly females, high incidence of lateral phase difference, atrophic change, anterior gap, and asymmetry were observed. CONCLUSIONS The results show that the behaviors of vocal fold vibrations were diverse even in healthy subjects with no vocal complaints or history of laryngeal diseases, and hence, the diversity of vocal fold vibrations in normal subjects must be taken into account in evaluating vocal fold vibrations.

Vocal Fold Atrophy in a Japanese Tertiary Medical Institute: Status Quo of the Most Aged Country

OBJECTIVE Voice problems in the geriatric population are increasing worldwide. Since the demographic research of geriatric voice patients in Japan, the country of the most advanced Aging Society, is missing, the authors assessed the current trend of geriatric voice patients, especially patients with presbylarynx at a tertiary medical institute of Japan. STUDY DESIGN Retrospective study. METHODS From a review of the medical records of newly referred patients, patients aged 65 years and older and patients with vocal fold atrophy were selected, and demographic data, questionnaires, and parameters of aerodynamic and acoustic study, and videostroboscopy were analyzed in terms of age and gender. Subsequently, the difference between patients with presbylarynx and 20 vocally healthy elderly subjects were assessed with multivariate analysis. RESULTS Of 1157 newly referred patients seen at the Voice Outpatient Clinic between 2006 and 2012, patients aged 65 years and older accounted for 37% (428 patients): there was 7% increase during the past 7 years and the prevalence was considerably higher than any other previous reports. Vocal fold atrophy accounted for 11% (128 patients) of all patients: dysphonia in patients with vocal fold atrophy aggravated as age advanced; there was a gender difference; and multivariate analysis revealed that reflux laryngitis, chronic medical condition, and vocal abuse were risk factors of presbylarynx. CONCLUSION In Japan, elderly dysphonic patients were prevalent and rapidly increasing in recent years. Age- and gender-related differences should receive attention. Preventive approach on risk factors such as reflux laryngitis, chronic medical condition, and vocal abuse should be considered in the management of presbylarynx.

Phase Difference of Vocally Healthy Subjects in High-Speed Digital Imaging Analyzed With Laryngotopography

BACKGROUND To elucidate the vibratory patterns of the vocal folds in normophonic subjects, we conducted a prospective study with laryngotopography, an analyzing technique for high-speed digital imaging to intuitively grasp spatial characteristics of vocal fold vibrations by pixel-wise discrete Fourier transform for brightness curve. MATERIALS AND METHODS Vocally healthy volunteer subjects with neither vocal complaint nor history of laryngeal diseases were divided into young (aged 35 years and younger) and elderly groups (aged 65 years and older), and high-speed digital images of phonations at a conversational frequency were analyzed with laryngotopography: phase differences (PDs) in the anterior-posterior (longitudinal) direction and in the left-right (lateral) direction were assessed. RESULTS Twenty-six young subjects (nine men and 17 women with a mean age of 27 years) and 20 elderly subjects (eight men and 12 women with a mean age of 73 years) were assigned to our study. In longitudinal PD, posterior-to-anterior opening type was significantly frequent in young women (all subjects: 43% and young women: 94%; P<0.001), whereas anterior-to-posterior opening type was significantly frequent in elderly men (all subjects: 39% and elderly men: 88%; P<0.001). There were no age- or gender-related differences in lateral PD (all subjects: 65%; P=0.880). DISCUSSIONS Both longitudinal and lateral PDs were widely observed even in vocally healthy subjects. Furthermore, the age- and gender-specific characteristics were also classified. Laryngotopography serves as a powerful tool to quantitatively characterize the vibratory patterns of vocal folds in vocally healthy subjects.

Characteristics of Vocal Fold Vibrations in Vocally Healthy Subjects: Analysis With Multi-Line Kymography

PURPOSE In this study, the authors aimed to analyze longitudinal data from high-speed digital images in normative subjects using multi-line kymography. METHOD Vocally healthy subjects were divided into young (9 men and 17 women; Mage = 27 years) and older groups (8 men and 12 women; Mage = 73 years). From high-speed digital images of phonation at a conversational frequency kymograms were created at 5 different levels of the vocal fold and were analyzed to determine the opening/closing longitudinal phase difference, open quotient, and speed index. Then age- and gender-related differences of these parameters were analyzed statistically. RESULTS Young women frequently showed a pattern of posterior-to-anterior glottal opening and anterior-to-posterior glottal closure, and older women demonstrated various opening and closing patterns. Both young men and older men were similar to older women. The open quotient was maximal at the most posterior glottal level in young women, but it tended to be maximal at the anterior glottis in the other subgroups. The mean value of the 5 open quotients was largest in young women. The mean speed index had a large negative value in older subjects. CONCLUSION This study provides the first information about age-related differences of longitudinal oscillatory characteristics of the vocal folds obtained with high-speed digital imaging.

Estimation of inferior-superior vocal fold kinematics from high-speed stereo endoscopic data in vivo

Despite being an indispensable tool for both researchers and clinicians, traditional endoscopic imaging of the human vocal folds is limited in that it cannot capture their inferior-superior motion. A three-dimensional reconstruction technique using high-speed video imaging of the vocal folds in stereo is explored in an effort to estimate the inferior-superior motion of the medial-most edge of the vocal folds under normal muscle activation in vivo. Traditional stereo-matching algorithms from the field of computer vision are considered and modified to suit the specific challenges of the in vivo application. Inferior-superior motion of the medial vocal fold surface of three healthy speakers is reconstructed over one glottal cycle. The inferior-superior amplitude of the mucosal wave is found to be approximately 13 mm for normal modal voice, reducing to approximately 3 mm for strained falsetto voice, with uncertainty estimated at σ ≈ 2 mm and σ ≈ 1 mm, respectively. Sources of error, and their relative effects on the estimation of the inferior-superior motion, are considered and recommendations are made to improve the technique.

Vocal Fold Vibration in Vocal Fold Atrophy: Quantitative Analysis With High-Speed Digital Imaging.

INTRODUCTION Vocal fold vibrations of vocal fold atrophy (VFA), a rapidly increasing voice disorder owing to worldwide societal aging, have not been clarified by high-speed digital imaging (HSDI). METHODS The HSDI method was performed on 46 patients (33 males and 13 females) with VFA and 20 vocally healthy subjects (8 males and 12 females), and the obtained data were quantitatively evaluated by frame-by-frame analysis, laryngotopography, single- and multi-line kymography, and glottal area waveform. RESULTS Overall, patients with VFA revealed larger open quotients, larger lateral phase difference, larger integral glottal width (the average glottal width over a glottal cycle), and smaller speed index than vocally healthy subjects. Some gender difference was noted: in males, lateral phase difference was not significant; and in females, integral glottal width and speed index were not significant. Correlation study revealed moderate correlations between HSDI-derived parameters and conventional acoustic or aerodynamic parameters. CONCLUSIONS The combination of multiple HSDI analysis methods was effective in documenting the characteristics of vocal fold vibrations in VFA. The knowledge of general vibratory characteristics and gender difference is beneficial for the appropriate clinical care of VFA.

Quantification of Vocal Fold Vibration in Various Laryngeal Disorders Using High-Speed Digital Imaging.

OBJECTIVE To quantify vibratory characteristics of various laryngeal disorders seen by high-speed digital imaging (HSDI). METHODS HSDI was performed on 78 patients with various laryngeal disorders (20 with polyp, 16 with carcinoma, 13 with leukoplakia, 6 with vocal fold nodule, and 33 with others) and 29 vocally healthy subjects. Obtained data were quantitatively evaluated by frame-by-frame analysis, laryngotopography, digital kymography, and glottal area waveform. RESULTS Overall, patients with laryngeal pathologies showed greater asymmetry in amplitude, mucosal wave and phase, smaller mucosal wave, and poorer glottal closure than vocally healthy subjects. Furthermore, disease-specific vibratory disturbances that generally agreed with the findings in the literature were quantified: comparing polyp with nodule, differences were noted in longitudinal phase difference, amplitude, and mucosal wave. In comparison with leukoplakia and cancer, nonvibrating area was more frequently noted in cancer. CONCLUSIONS The HSDI analysis of various voice disorders using multiple methods can help phonosurgeons to properly diagnose various laryngeal pathologies and to estimate the degree of their vocal disturbances.

Visualization and Estimation of Vibratory Disturbance in Vocal Fold Scar Using High-Speed Digital Imaging

OBJECTIVE To explore the method to visualize and quantify the abnormality of vocal fold vibration in vocal fold scar (VFS) using high-speed digital imaging (HSDI). METHODS HSDI was performed on 12 patients (2 men and 10 women) with VFS and 46 vocally healthy subjects (17 men and 29 women), and the obtained data were quantitatively evaluated by frame-by-frame analysis, laryngotopography (LTG), single-line and multiline kymography, and glottal area waveform. RESULTS Visualization of a scarred area was feasible in 75% of VFS in the present study using LTG. Quantitative HSDI analysis revealed that VFS had poorer glottal closure (eg, larger open quotients, larger minimal glottal area), reduced vibration in a scarred area (eg, smaller mucosal wave magnitude, mucosal wave persistence, lateral peak index), and greater asymmetry (eg, amplitude difference, mucosal wave magnitude difference, lateral phase difference) than the control group. Correlation study revealed moderate correlations between HSDI-derived parameters and conventional acoustic or aerodynamic parameters (eg, period perturbation quotient). CONCLUSIONS HSDI is considered to be useful in the diagnosis of VFS, visualization of a scarred area, and quantification of vibratory abnormality.

Relationship of Various Open Quotients With Acoustic Property, Phonation Types, Fundamental Frequency, and Intensity

INTRODUCTION In the present study, we examined the relationship between various open quotients (Oqs) and phonation types, fundamental frequency (F0), and intensity by multivariate linear regression analysis (MVA) to determine which Oq best reflects vocal fold vibratory characteristics. METHODS Using high-speed digital imaging (HSDI), a sustained vowel /e/ at different phonation types, F0s, and intensities was recorded from six vocally healthy male volunteers: the types of phonation included modal, falsetto, modal breathy, and modal pressed phonations; and each phonation was performed at different F0s and intensities. Electroglottography (EGG) and sound signals were simultaneously recorded with HSDI. From the obtained data, 10 conventional Oqs (four Oqs from the glottal area function, four kymographic Oqs, and two EGG-derived Oqs) and two newly introduced Oqs (Oq(edge)+ and Oq(edge)) were evaluated. And, relationships between various Oqs and phonation types, F0, and intensity were evaluated by MVA. RESULTS Among the various Oqs, Oq(edge)+ and Oq(edge) revealed the strongest correlations with an acoustic property and could best describe changes in phonation types: Oq(edge) was found to be better than Oq(edge)¯. Oq(MLK), the average of five Oqs from five-line multiline kymography was a very good alternative to Oq(edge)¯. EGG-derived Oqs were able to differentiate between modal phonation and falsetto phonation, but it was necessary to consider the change of F0 simultaneously. MVA showed the changes in Oq values between modal and other phonation types, the degree of involvement of intensity, and no relationship between F0 and Oqs. CONCLUSIONS Among Oqs evaluated in this study, Oq(edge)+ and Oq(edge) were considered to best reflect the vocal fold vibratory characteristics.

An Aerodynamic Study of Phonations in Patients With Parkinson Disease (PD)

BACKGROUND The precise comparison of the voice characteristics of Parkinson disease (PD) patients with age-matched normal subjects is still one of the important research projects. The present study aimed at comparing the voice characteristics in sustained phonations of PD patients with an age-matched control group. METHODS The subjects were 30 Japanese PD patients (15 males and 15 females). The control group consisted of 30 age-matched normal Japanese subjects (15 males and 15 females). Each subject was required to phonate into a mouthpiece attached to Vocal Function Analyzer (PS-77E; Nagashima Medical Instrumental Corporation, Tokyo, Japan) with the airway interruption system, and expiratory lung pressure, mean flow rate, fundamental frequency and intensity of voice, and pitch range were measured. Maximum phonation time was also assessed. RESULTS The highest pitch level was significantly lower in the PD group than that of the control group in both sexes, whereas the lowest pitch level was significantly higher in the PD group only in males. In both sexes, the pitch range was significantly narrower in the PD group than in the control group. There was no significant difference in intensity, mean flow rate, expiratory pressure, or maximum phonation time between the two groups, for both males and females. CONCLUSION Only remarkable difference in the voice characteristics between PD patients and age-matched normal elderlies was limited to the narrowing of the pitch range in PD patients. The restriction in pitch regulation in PD patients was considered to be because of difficulty in reciprocal control of the laryngeal muscles secondary to latent rigidity.