Laryngeal adduction in resonant voice

The primary question in this study was whether subjects with nodules and subjects with healthy larynges would produce “resonant voice” with a similar laryngeal configuration. A second question regarded whether the electroglottographic closed quotient (EGG CQ) could be used to noninvasively distinguish resonant from other voice types. Twelve adult singers and actors served as subjects, including 6 persons with healthy larynges and 6 persons with nodules. Performers were used as an attempt to maximize token validity and stability. Subjects produced repeated tokens of resonant, pressed, normal, and breathy voice during sustained vowels. Laryngeal adduction was directly estimated using blinded, ordinal, visual-perceptual ratings based on videoscopic views of the larynx. EGG CQs were further calculated based on separate trials. The perceptual ratings indicated that subjects in both groups produced resonant voice with a barely adducted or barely abducted laryngeal configuration that was distinct from configurations for pressed and breathy (but not normal) voice. Previous literature suggests that this configuration may be relevant in many cases of voice therapy (I). Average CQs distinguished resonant from pressed voice, but inconsistently distinguished resonant from breathy voice. Further CQs were reliably different across healthy subjects and subjects with nodules. Thus, the utility of this measure to noninvasively estimate resonant voice may be limited, particularly without ongoing subject-specific calibration procedures.     

Vocal Range and Intensity in Actors: A Studio Versus Stage Comparison

A voice range profile (VRP) was obtained from each of eight professional actors and compared with two speech range profiles (SRPs). One speech profile was obtained during the dramatic reading of a scene in the laboratory and the other during a performance on stage in a professional theater. The objective was to determine the pitch and loudness ranges used by the actors in speech relative to the VRP. The principal question of interest was whether the actors stayed within the center of the VRP, or whether they tended to drift toward the boundaries of intensity and frequency. A second question was whether the performance within the laboratory accurately reflects that of a stage performance. The results suggest that some subjects tend to exceed the center of the VRP during the stage performance. It is hypothesized that these actors may stress their vocal mechanism during performance and are more likely candidates for vocal injury.     

Long-Term Horizontal Vocal Directivity of Opera Singers: Effects of Singing Projection and Acoustic Environment

Vocal directivity refers to how directional the sound is that comes from a singer's mouth, that is, whether the sound is focused into a narrow stream of sound projecting in front of the singers or whether it is spread out all around the singer. This study investigates the long-term vocal directivity and acoustic power of professional opera singers and how these vary among subjects, among singing projections, and among vastly different acoustic environments. The vocal sound of eight professional opera singers (six females and two males) was measured in anechoic and reverberant rooms and in a recital hall. Subjects sang in four different ways: (1) paying great attention to intonation; (2) singing as in performance, with all the emotional connection intended by the composer; (3) imagining a large auditorium; and (4) imagining a small theatre. The same song was sung by all singers in all conditions. A head and torso simulator (HATS), radiating sound from its mouth, was used for comparison in all situations. Results show that individual singers have quite consistent long-term average directivity, even across conditions. Directivity varies substantially among singers. Singers are more directional than the standard HATS (which is a physical model of a talking person). The singer's formant region of the spectrum exhibits greater directivity than the lower-frequency range, and results indicate that singers control directivity (at least, incidentally) for different singing conditions as they adjust the spectral emphasis of their voices through their formants.     

The abduction quotient related to vocal quality

The abduction quotient, a measure of effective glottal width, was obtained for electroglottographic recordings from a professional operatic baritone singer. The subject produced repeated tokens of the voice qualities breathy, normal, and pressed (or constricted) in both a speech and a singing manner. In the singing manner, the subject produced the three vocal qualities at three pitch levels and three loudness levels. The abduction quotient decreased from breathy to pressed voice, suggesting that the measure corresponds to effective glottal width. The measure was found to be consistently low during all conditions of singing, suggesting that the subject produced all singing tokens with relatively strong laryngeal adduction at the vocal process level. Although the results of this study support the validity and usefulness of the abduction quotient, further verification is needed.     

Laryngeal airway resistance in teacherswith vocal fatigue: A preliminary study

A noninvasive pressure-flow technique was used to compare laryngealairway resistances in nine female classroom teachers with symptoms of vocal fatigue and seven teachers without symptoms of vocal fatigue. Data were collected two times per day on the Monday, Wednesday, and Friday of a typical work-week. No significant between-group differences were found, but two within-group differences were notable. Airflow in the fatigued subjects decreased across the sampling period (p = .0009). In the controls, air pressure increased across the sampling period (p = .021). These findings suggest that both groups may have reacted to vocal demands during the week by employing two different strategies to maintain habitual laryngeal airway resistance: laryngeal adjustments alone or laryngeal adjustments plus increased respiratory drive. The first strategy, employed by the fatigued subjects, may have been less efficient, thereby provoking conditions associated with their vocal fatigue.     

Objective Voice Quality Analysis Before and After Onset of Unilateral Vocal Fold Paralysis

This study was designed to investigate objective voice quality measurements in unilateral vocal fold paralysis (UVFP) by eliminating intersubject variability. To our knowledge this is the first report objectively analyzing paralytic dysphonia as compared to the same voice before onset of UVFP. The voices of two male subjects were prospectively recorded before and after the onset of iatrogenic UVFP (thoracic surgery).The following acoustic measurements of the vowel /a/ were performed using the CSL and MDVP (Kay Elemetrics): jitter, shimmer, harmonics-to-noise ratio, cepstral peak prominence, the relative energy levels of the first harmonic, the first formant and the third formant, the spectral slope in the low-frequency zone (0-1 kHz and 0-2 kHz), and the relative level of energy above 6 kHz. Distribution of spectral energy was analyzed from a long-term average spectrum of 40 seconds of text. Laryngeal aerodynamic measurements were obtained for one patient before and after onset of paralysis using the Aerophone II (Kay Elemetrics). Pitch and amplitude perturbation increased secondary to UVFP, while the harmonics-to-noise ratio and the cepstral peak prominence decreased. A relative increase in the mid-frequency and high-frequency ranges and a decrease in the low-frequency spectral slope were observed. Mean airflow rate and intraoral pressure increased, and glottal resistance and vocal efficiency decreased secondary to UVFP. The findings of this self-paired study confirm some but not all the results of previous studies. Measures involving the fundamental and the formants did not corroborate previous findings. Further investigation with vocal tract modeling is warranted.     

G. Paul Moore lecture: Rational thought: The impact of voice science upon voice care

Recent evolution in scientific knowledge and technology has led to monumental improvement in the standard of care for patients with voice disorders. New concepts in anatomy, physiology, measurement, and analysis have provided voice care professionals with not merely better understanding, but moreover an extensive vocabulary with which to think about voice function and dysfunction. Previously, we had to depend too much upon anecdote and “the art of medicine.” Thanks to scientific advances, we now have the tools we need for rational thought about the human voice. This is the fundamental change responsible for recent great advances in voice care.     

The Value of Laryngeal Electromyography in the Evaluation of Laryngeal Motion Abnormalities

SUMMARY: Laryngeal electromyography (EMG) functions routinely as a prognostic tool in the evaluation of vocal fold paralysis, as a guide for therapeutic injections into the laryngeal muscles, and more recently as an assessment tool in the evaluation of vocal fold paresis. This study investigates the clinical utility of laryngeal EMG as a diagnostic aid in the evaluation of movement disorders of the larynx in patients complaining of dysphonia. A retrospective chart review of all laryngeal EMGs performed at a tertiary laryngology referral center over a 13-month period was performed. All laryngeal EMGs were performed to evaluate laryngeal motion abnormalities in dysphonic patients. Thirty-seven laryngeal EMGs were completed during this study period. Analysis of the data revealed that the medical treatment plan changed as a result of findings on laryngeal EMG in 10/37 patients (27.0%); laryngeal EMG guided and/or confirmed the course of treatment in 12/37 patients (32.4%) and did not change the treatment plan in 15/37 patients (40.5%). Laryngeal EMG is a useful diagnostic tool that, in this study, contributed significantly to and helped guide the evaluation and management of motion disorders in the larynx of dysphonic patients.     

The False Vocal Folds: Shape and Size in Frontal View During Phonation Based on Laminagraphic Tracings

The geometry of the false vocal fold region during phonation is important to the understanding of the aerodynamics and acoustics of voice. The shape and dimensions of this region during phonation were estimated using laminagraphic tracings of the larynx. Laminagrams from two previous studies, one with non-singer subjects (Experiment I, Hollien and Colton, 1969) and the other with singers (Experiment II, Wilson, 1972), were traced, photocopied, and measured. Statistical analysis showed significantly greater false vocal fold height in males than females for both experiments. The false vocal fold gap was also significantly greater in males than females for Experiment II, but reached only borderline significance for Experiment I. For each gender, most of the linear measures were greater in Experiment I when compared to Experiment II; these differences may be passive in nature (due to actual differences in subject size) or active (due to muscle contraction that displaced the false vocal folds during singing).     

The Impact of Voice Disorders Among Teachers: Vocal Complaints, Treatment-Seeking Behavior, Knowledge of Vocal Care, and Voice-Related Absenteeism

Objectives

Teachers are at increased risk for developing voice disorders. Occupational risk factors have been extensively examined; however, little attention has been paid to the consequences of the vocal complaints. The objective of this study was to investigate the knowledge that teachers have about vocal care, treatment-seeking behavior, and voice-related absenteeism.

Methods

The study group comprised 994 teachers and 290 controls whose jobs did not involve vocal effort. All participants completed a questionnaire inquiring about vocal complaints, treatment-seeking behavior, voice-related absenteeism, and knowledge about vocal care. Comparisons were made between teachers with and without vocal complaints and with the control group.

Results

Teachers reported significantly more voice problems than the control population (51.2% vs 27.4%) (χ² = 50.45, df = 1, P < 0.001). Female teachers reported significantly higher levels of voice disorders than their male colleagues (38% vs 13.2%, χ² = 22.34, df = 1, P < 0.001). Teachers (25.4%) sought medical care and eventually 20.6% had missed at least 1 day of work because of voice problems. Female teachers were significantly more likely to seek medical help (χ² = 7.24, df = 1, P = 0.007) and to stay at home (χ² = 7.10, df = 1, P = 0.008) in comparison with their male colleagues. Only 13.5% of all teachers received information during their education.

Conclusions

Voice disorders have an impact on teachers' personal and professional life and imply a major financial burden for society. A substantial number of teachers needed medical help and was obligated to stay at home because of voice problems. This study strongly recommends the implementation of vocal education during the training of teacher students to prepare the vocal professional user.     

Acoustic concomitants of emotional expression in operatic singing: The case of lucia in Ardi gli incensi

Two excerpts from the cadenza in Ardi gli incensi from Donizetti's opera Lucia di Lammermoor were acoustically analyzed for five recorded versions of the cadenza by Toti dal Monte, Maria Callas, Renata Scotto, Joan Sutherland, and Edita Gruberova. These acoustic parameters of the singing voices were correlated with preference and emotional expression judgments, based on pairwise comparisons, made by a group of experienced listener-judges. In addition to showing major differences in the voice quality of the five “dive” studied, the acoustic parameters suggested which vocal cues affect listener judgments. Two component scores, based on a factorial-dimensional analysis of the acoustic parameters, predicted 84% of the variance in the preference ratings.