Characteristics of Phonatory Function in Singers and Nonsingers With Vocal Fold Nodules

Purpose

The goals of this study were to determine if there were significant differences between singers and nonsingers in the morphology of vocal nodules and the associated impact on vocal function.

Method

Participants were 10 professionally trained singers with nodules, eight nonsingers with nodules, and 10 individuals with healthy normal voice (controls). Surface electromyography (sEMG) from three anterior neck locations and acoustic rise times for vowels /a/ and /i/ were measured in all the participants. In individuals with nodules, dB SPL/cm H₂O, glottal airflow, and nodule location and size were also measured.

Results

There were no significant differences between singers and nonsingers with nodules in terms of airflow, dB SPL/cm H₂O, nodule size, or nodule location. In nonsingers with nodules, airflow and nodule size were significantly correlated, but were not significantly correlated in singers. Vowel rise times and sEMG during vocal tasks did not differentiate among nodule and control groups. Sternocleidomastoid sEMG during initiation of the vowel /a/ was statistically significantly stronger in nonsingers with nodules relative to singers with nodules and controls.

Conclusions

Nodule morphology did not differ between singers and nonsingers, although some behavioral aspects of phonation differed between the groups.     

Objective measures of voice production in patients complaining of laryngeal fatigue

The purpose of this retrospective study is to describe results of acoustic, aerodynamic, and videostroboscopic measures in patients complaining of laryngeal fatigue. Data were collected from 88 patients whose primary complaint was chronic laryngeal fatigue in the absence of visible laryngeal pathologies. The results revealed an abnormally high airflow rate and decreased maximum phonation time. An anterior glottal chink, anterior and posterior glottal chinks, or spindle-shaped glottal closure were found in 61% of the subjects.     

Glottal closure, transglottal airflow, and voice quality in healthy middle-aged women

Seventeen healthy women, 45 to 61 years old, were examined using videofiberstroboscopy during phonation at three loudness levels. Two phoniatricians evaluated glottal closure using category and ratio scales. Transglottal airflow was studied by inverse filtering of the oral airflow signal recorded in a flow mask (Glottal Enterprises System) during the spoken phrase /ba:pa:pa:pa:p/ at three loudness levels. Subglottal pressure was estimated from the intraoral pressure during p occlusion. Running speech and the repeated /pa:/ syllables were perceptually evaluated by three speech pathologists regarding breathiness, hypo-, and hyperfunction, using continuous scales. Incomplete glottal closure was found in 35 of 46 phonations (76%). The degree of glottal closure increased significantly with raised loudness. Half of the women closed the glottis completely during loud phonation. Posterior glottal chink (PGC) was the most common gap configuration and was found in 28 of 46 phonations (61%). One third of the PGCs were in the cartilaginous glottis (PGCc) only. Two thirds extended into the membranous portion (PGCm); most of these occurred during soft phonation. Peak flow, peak-to-peak (AC) flow, and the maximum rate of change for the flow in the closing phase increased significantly with raised loudness. Minimum flow decreased significantly from normal to loud voice. Breathiness decreased with increased loudness. The results suggest that the incomplete closure patterns PGCc and PGCm during soft phonation ought primarily to be regarded as normal for Swedish women in this age group.     

Glottic Characteristics and Voice Complaint in the Elderly

This study evaluated the relationship between voice complaint and deviant vocal fold status with special regard to presbylarynx, in patients aged more than 60 years, with pharyngeal-laryngeal complaint. The material consisted of clinical histories and images obtained by laryngoscopies from protocols from the Larynx Institute-INLAR, Sao Paulo, Brazil, of 210 patients, 88 men and 122 women, aged more than 60 years, who had sought otorhinolaryngologic treatment. Indicative glottic characteristics of the presbylarynx, such as vocal fold bowing, prominence of vocal processes, and spindle-shaped glottic chink, were analyzed. The increase in mass, leukoplakia, and other vocal fold alterations, distinct from these two, grouped as miscellaneous, as well as the presence or absence of voice complaint were also analyzed. Vocal fold bowing, prominence of vocal processes, and spindle-shaped glottic chink showed a strong correlation among each other. The presence of presbylarynx was accompanied by less voice complaint than the presence of vocal fold mucosa alterations, which in turn are more common where an absence of presbylarynx exists.     

Simultaneous analysis of vocal fold vibration and transglottal airflow: exploring a new experimental setup

The purpose of this study was to develop an analysis system for studying the relationship between vocal fold vibration and the associated transglottal airflow. Recordings of airflow, electroglottography (EGG), oral air pressure, and acoustic signals were performed simultaneously with high-speed imaging at a rate of approximately 1900 frames/s. Inverse filtered airflow is compared with the simultaneous glottal area extracted from the high-speed image sequence. The accuracy of the synchronization between the camera images and the foot pedal synchronization pulse was examined, showing that potential synchronization errors increase with time distance to the synchronization pulse. Therefore, analysis was limited to material near the synchronization pulse. Results corroborate previous predictions that air flow lags behind area, but also they reveal that relationships between these two entities may be complex and apparently varying with phonation mode.     

激励电压对沿面介质阻挡放电特性的影响分析

近年来, 沿面介质阻挡放电(SDBD) 用作大气压下气流控制的等离子体激励器因其众多的优点受到了广泛的关注. 然而, 国内外对沿面介质阻挡放电及其应用的研究尚处于探索阶段, 对其放电特性的影响因素缺乏规律性的认识. 因此, 对SDBD 相关特性和影响因素进行研究具有重要理论意义和应用价值. 本文使用频率5 ~20 kHz,峰值电压0~30 kV 的可调正弦交流电源激励大气压环境下的 SDBD 装置. 通过调节激励电压大小, 研究了其与SDBD 放电特性之间的关系, 对等离子体放电电流、 放电形貌、 功率损耗、 诱导气流以及机械效率进行了分析. 实验结果表明,SDBD 消耗功率、 放电强度和诱导气流均会随着激励电压的增大而增大, 但机械效率存在先增大后减小的趋势, 说明等离子体流动控制中研究中存在最佳效率点.     

Chink antenna in the long line approximation

We give proofs for the sinusoidal nature of the current distribution over an insulated chink antenna with allowance for finite dimensions of the antenna, its feeder region, and the layer of environmental inhomogeneity. The problem of tuning of a chink antenna to resonance is considered in detail, and the possibility of detecting the inhomogeneity of the ambient medium by the antenna detuning is shown. Institute of Atomic Energy, Obninsk, Kaluga region, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 40, No. 4, pp. 432–440, April, 1997.     

Glottal airflow and transglottal air pressure measurements for male and female speakers in soft, normal, and loud voice

Measurements on the inverse filtered airflow waveform (the "glottal waveform") and of estimated average transglottal pressure and glottal airflow were made from noninvasive recordings of productions of syllable sequences in soft, normal, and loud voice for 25 male and 20 female speakers. Statistical analyses showed that with change from normal to loud voice, both males and females produced loud voice with increased pressure, accompanied by increased ac flow and increased maximum airflow declination rate. With change from normal voice, soft voice was produced with decreased pressure, ac flow and maximum airflow declination rate, and increased dc and average flow. Within the loudness conditions, there was no significant male-female difference in air pressure. Several glottal waveform parameters separated males and females in normal and loud voice. The data indicate higher ac flow and higher maximum airflow declination rate for males. In soft voice, the male and female glottal waveforms were more alike, and there was no significant difference in maximum airflow declination rate. The dc flow did not differ significantly between males and females. Possible relevance to biomechanical differences and differences in voice source characteristics between males and females and across loudness conditions is discussed.     

Vocal Intensity Characteristics inNormal and Elderly Speakers

The relationship of lung pressure, fundamental frequency, peak airflow, open quotient, and maximal flow declination rate to vocal intensity for a normal speaking, young male control group and an elderly male group was investigated. The control group consisted of 17 healthy male subjects with a mean age of 30 years and the elderly group consisted of 11 healthy male subjects with a mean age of 77 years. Data were collected at three levels of vocal intensity: soft, comfortable, and loud, corresponding to 25%, 50%, and 75% of dynamic range, respectively. Phonational threshold pressure and lung pressure were obtained using the intraoral technique. The oral airflow waveform was inverse filtered to provide an approximation to the glottal airflow waveform from which measures of fundamental frequency, peak airflow, open quotient, and maximal flow declination rate were determined. Excess lung pressure was calculated as lung pressure minus estimated phonational threshold pressure. The results show for both groups an increase in sound pressure level across the conditions, with corresponding increases in lung pressure, excess lung pressure, fundamental frequency, peak airflow, and maximal flow declination rate. Open quotient decreased with increasing vocal intensity. Lung pressure, sound pressure level, and peak airflow were all found to be significantly greater for the control group than for the elderly group at each condition. Open quotient was found to be significantly lower in the control group than in the elderly group at each condition. No significant difference was observed for excess lung pressure, phonational threshold pressure, fundamental frequency, or maximal flow declination rate between the two groups. These results show that a difference in vocal intensity does exist between young and elderly voices and that this difference is the result of differences in lung pressure, peak airflow, and open quotient.     

The interrelationship of subglottic air pressure, fundamental frequency, and vocal intensity during speech

In this study we have simultaneously measured subglottic air pressure, airflow, and vocal intensity during speech in nine healthy subjects. Subglottic air pressure was measured directly by puncture of the cricothyroid membrane. The results show that the interaction between these aerodynamic properties is much more complex that previously believed. Certain trends were seen in most individuals, such as an increase in vocal intensity with increased subglottic air pressure. However, there was considerable variability in the overall aerodynamic properties between subjects and at different frequency and intensity ranges. At certain frequencies several subjects were able to generate significantly louder voices without a comparable increase in subglottic air pressure. We hypothesize that these increases in vocal efficiency are due to changes in vocal fold vibration properties. The relationship between fundamental frequency and subglottic pressure was also noted to vary depending on vocal intensity. Possible mechanisms for these behaviors are discussed.     

Efficient charge neutralization with an ac corona ionizer

This paper discusses the problem of obtaining effective charge neutralization by an ac corona ionizer with airflow. The motion of ions and the neutralization of a charged object for different discharge frequencies and airflow velocities are investigated by a computer fluid model for positive and negative ions. The results of the investigation show that, in the region of ion transport, the quasi-neutralized charge distribution self-generated by positive and negative ions during charge neutralization can effectively transport the ions themselves from an ionizer to a charged object and significantly reduce both the unwanted fluctuation and dc offset in the potential of the object at a steady state, resulting in efficient and precise charge neutralization. Since the quasi-neutralization greatly depends on the relationship between the discharge frequency and airflow velocity, the control of the relationship may lead to better neutralization with an air-blowing ac ionizer.     

On-line Surface Area Measurement of Concentrated Slurries using low field spin-lattice relaxation NMR

A method for the rapid on-line determination of surface area and solids content in flowing concentrated slurries using low field NMR spin-lattice relaxation measurements has been developed and demonstrated. The relationship between flow and spin-lattice relaxation time (T₁) of protons in water at 20 MHz was examined using aqueous copper sulfate solutions. The ability to measure surface area and solids concentration in both stagnant (stopped flow) and flowing systems via NMR was demonstrated using several different concentrated aqueous titania and glass slurries (20 to 80 weight percent) for which the dried powder surface area was previously determined via nitrogen adsorption/BET analysis and the solids content determined gravimetrically. Surface areas were also calculated from particle size analysis and found to vary by up to an order of magnitude from the adsorption and NMR results.     

三电极共面介质阻挡放电的放电特性及诱导气流实验研究

等离子体流动控制激励器由于其响应速度快、激励频带宽、能量损耗低、可靠性强的优势,在航空航天领域的主动流动控制等方面得到了广泛应用.文章提出了一种新型的等离子体气动激励器——三电极共面介质阻挡放电激励器,研究了该激励器电极结构对放电特性和诱导气流速度的影响,并与传统共面介质阻挡放电和沿面介质阻挡放电激励器进行了比较.结果表明:（1）随着激励电压的提高,高压电极和地电极之间先出现了丝状放电并逐渐延伸到第三电极;（2）随着第三电极与高压电极之间的距离增大,诱导气流速率从2.4 m/s下降到0 m/s,而第三电极宽度的变动对诱导气流速度影响可忽略不计;（3）相同外部条件下,该激励器诱导的气流速度小于沿面介质阻挡放电激励器,但高于共面介质阻挡放电激励器.      

The frequency of hard glottal attacks in patients with muscle tension dysphonia, unilateral benign masses and bilateral benign masses

Hard or abrupt glottal attack (HGA) is one of the vocal behaviors often associated with benign lesion of the vocal folds. This study was designed to determine whether the frequency of HGA was different in hyperfunctional voice patients with and without vocal fold masses. One hundred and forty-seven subjects were studied. All subjects received a complete otolaryngological evaluation including strobovideolaryngoscopy, objective voice measures, and evaluation by a speech-language pathologist. Thirty-two patients were diagnosed with muscle tension dysphonia (19 male, 13 female) without vocal fold masses. Fifty-seven patients were diagnosed with unilateral vocal fold masses (29 male, 28 female), most of which were cysts. Fifty-eight patients were diagnosed with bilateral vocal fold masses (13 male, 45 female). Of the 45 females with bilateral vocal fold masses. 26 had a vocal cyst and reactive nodule and 19 had bilateral vocal fold nodules. The control group was balanced and matched based on sex and on percentage of singers and nonsingers. It consisted of 49 subjects with no vocal fold pathology (20 male, 29 female). The group was composed of professional speakers, singers, and nonprofessional speakers. All voice disordered groups demonstrated higher frequencies of HGA than the control group. Differences were found between the male and female subjects in this study. No differences were found between the various disorders. Differences were also found between the subgroups of bilateral masses, where the bilateral nodules group presented a higher frequency of HGA than the cyst and contralateral reactive nodule.     

Laryngeal Mechanisms During Human 4-kHz Vocalization Studied With CT, Videostroboscopy, and Color Doppler Imaging

The objective of this study was to investigate the underlying laryngeal mechanisms during the specific human 4-kHz vocalization. The laryngeal configuration during this vocalization was measured using high-resolution computerized tomographic scan and videostrobolaryngoscopy. The color Doppler imaging (CDI) of medical ultrasound was used to detect the vibrations of glottal and supraglottal mucosa. During the 4-kHz vocalization, the ventricular folds were adducted in the shape of a bimodal chink and the vocal folds were shaped as a "V" with an opening at the posterior glottis. In the coronal view, the laryngeal ventricles had collapsed and a divergent shaped conduit was observed at the posterior portion of the larynx. The surface mucosa vibration detected by CDI was noted over the bilateral ventricular folds and aryepiglottic folds. The vibration displacement was estimated to be on the order of 0.1mm. This vibration amplitude was too small to be detected in videostrobolaryngoscopy. The laryngeal configuration and CDI data suggested a diffuser jet with periodic vorticity bursts in the larynx producing 4 kHz voice.     

Phonatory control in male singing: A study of the effects of subglottal pressure, fundamental frequency, and mode of phonation on the voice source

This article describes experiments carried out in order to gain a deeper understanding of the mechanisms underlying variation of vocal loudness in singers. Ten singers, two of whom are famous professional opera tenor soloists, phonated at different pitches and different loudnesses. Their voice source characteristics were analyzed by inverse filtering the oral airflow signal. It was found that the main physiological variable underlying loudness variation is subglottal pressure (Ps). The voice source property determining most of the loudness variation is the amplitude of the negative peak of the differentiated flow signal, as predicted by previous research. Increases in this amplitude are achieved by (a) increasing the pulse amplitude of the flow waveform; (b) moving the moment of vocal fold contact earlier in time, closer to the center of the pulse; and (c) skewing the pulses. The last mentioned alternative seems dependent on both Ps and the ratio between the fundamental frequency and the first formant. On the average, the singers doubled Ps when they increased fundamental frequency by one octave, and a doubling of the excess Ps over threshold caused the sound pressure level (SPL) to increase by 8–9 dB for neutral phonation, less if mode of phonation was changed to pressed. A shift of mode of phonation from flow over neutral to pressed was associated with a reduction of the peak glottal permittance i.e., the ratio between peak transglottal airflow to Ps. Flow phonation had the most favorable relationship between Ps and SPL.     

Formation of surface roughness on nanocrystalline aluminium samples under straining by molecular dynamics studies

The surface roughening of nanocrystalline aluminium samples was investigated by molecular dynamics simulations. Attention was focused on the fact that roughness increases with the grain size and the strain. The elastic–plastic transition was found at around 3.5% strain and a reverse Hall–Petch effect was observed under straining conditions. Then, different strain distributions in grains and grain boundaries at the sample surface were highlighted, yielding to the formation of local roughness. Finally, a linear relationship between the magnitude of roughness and the out-of-plane strain component was found.     

Videofluoroscopic and Laryngoscopic Evaluation of the Upper Airway and Larynx of Professional Bassoon Players

The bassoon is a demanding double-reed woodwind instrument requiring exquisite control of airflow and air pressure to the reed to produce desired tonal characteristics. Little information is available from direct visualization of the vocal tract and larynx of the bassoonist while playing. Of particular interest is the mechanism(s) of vibrato. This study was undertaken to understand more fully the mechanics of the upper airway in bassoonists during music production. Four adult bassoon players served as subjects. Three players were studied with both sound-synchronized videofluoroscopy and fiber-optic nasal endoscopy. The other subject was studied only by fiber-optic endoscopy. All subjects were evaluated while playing various scales and standard passages common in music pedagogy. The results from this study revealed several findings on the mechanics of upper airway activity during playing: (1) firm velopharyngeal closure was a prerequisite for maximal containment of air pressure and regulation of airflow in the oropharyngeal regions; (2) changes in the pitch and intensity were associated with differential expansion of the pharynx; (3) tongue activity was notable because of its shaping the size and shape of the airway, its role in regulating airflow to the reed, and its contributions to conditioning airflow in vibrato; and (4) slight vocal fold displacements from subglottal airflow and epiglottic movements from tongue base activity contributed to airway changes during vibrato. These seemed to further condition subglottal pressure trains derived primarily from expiration.     

Study on the mechanism of hardening polycrystals of solid solutions Cu-Ni,Cu-Zn,Cu-Al,and Cu-Ge at microdeformation stage

The stress-strain curves were obtained at the stage of microdeformation of polycrystals of the solid solutions Cu-Ni, Cu-Zn, Cu-Al, and Cu-Ge. It was demonstrated that the shape of the stress-strain curves below the yield point depends on the concentration, the distribution of atoms of alloying elements, the properties of the components of the alloy, and on the size of grain. The dependence of the modulus of strain hardening on the composition of the alloys and on the grain size was analyzed. It was concluded that the magnitude of the modulus of strain hardening at the initial stage of microdeformation is determined by the character of the involvement of the individual grains in plastic deformation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 86–92, December, 1972.     

An investigation on airflow in pathological nasal airway by PIV

Understanding of airflow characteristics in nasal cavity is closely related with the physiological functions, like air-conditioning and smelling, and pathological aspects in nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. The next step on this topic is naturally studies for disordered nasal airways and this is the main purpose of this article. Airflows in the pathological nasal airways, including nasal cavity and upper pharynx, of Korean adults are investigated experimentally by PIV measurement technique and air resistance measurements. Quantitative data for normal and pathological nasal airway are obtained. Average and RMS velocity distributions are obtained for inspirational and expirational nasal airflows. The CBC PIV algorithm with window offset is used for PIV flow analysis. PIV measurements of nasal airflow for nasal cavities with 50% and 70% adenoid vegetation are conducted for the first time. The asymmetric nasal cavities, due to either congenital deformity or injury, are also investigated. Comparisons in nasal airflows for both normal and abnormal cases are also appreciated and airflow characteristics that are related with the abnormalities in nasal cavity are proposed.