Consistency of Inhalatory Breathing Patterns in Professional Operatic Singers

Respiratory behavior is generally considered important to voice function, the assumption being that it affects the voice source. Accurate and consistent control of the voice source is particularly important in professional operatic singing. An erratic behavior of a factor influencing voice production is incompatible with a well-controlled vocal behavior. We analyzed the consistency of inhalatory breathing patterns during singing in five professional operatic singers, using the same material as in a previous investigation of phonatory breathing patterns. Rib cage (RC) and abdominal wall (AW) movements were recorded by respiratory inductive plethysmography. Consistency was analyzed in terms of the mean correlation between three takes of ten musical phrases. Results revealed a high consistency in lung volume (LV) change and RC movements in all singers and in AW movements in three singers. Consistency across different phrases was slightly lower. The results are compatible with the idea that inhalatory behavior is important to voice source in singing. A high correlation between LV change and RC movement was found in all singers and between LV change and AW movement in three. The contribution to LV change from RC was greater than that from AW in all singers.     

Trillo rates exhibited by professional early music singers

Trillo rates of nine professional early music singers were assessed from recordings made as they varied their repetition rate between slow and fast at the 25, 50, and 75% levels of their concert pitch ranges. Continuous trilli at all pitch levels formed two distinct clusters: slow trillo rates ranged from 2.0 to 6.9 Hz and fast extended from 7.5 to 12.4 Hz. Trillo rates did not differ as a function of singer's voice type, gender, age, experience, or location in the voice range.     

Differential phonatory characteristics of four women with amyotrophic lateral sclerosis

Patients with specific neural subsystem involvement are often reported to present with particular perceptual characteristics of voice. This has been true for diseases such as amyotrophic lateral sclerosis (ALS), a progressive disease in which mixed neurologic signs are present. This article reports acoustic data on the phonatory performance of four women diagnosed with ALS who had initial bulbar signs and progressive phonatory deterioration. The data presented here demonstrate that the phonatory characteristics of women with ALS are not uniform, but in fact may vary greatly from patient to patient.     

Estimating perceived phonatory pressedness in singing from flow glottograms

The normalized amplitude quotient (NAQ), defined as the ratio between the peak-to-peak amplitude of the flow pulse and the negative peak amplitude of the differentiated flow glottogram and normalized with respect to period time, has been shown to be related to glottal adduction. Glottal adduction, in turn, affects mode of phonation and hence perceived phonatory pressedness. The relationship between NAQ and perceived phonatory pressedness was analyzed in a material collected from a professional female singer and singing teacher who sang a triad pattern in breathy, flow, neutral, and pressed phonation in three different loudness conditions (soft, middle, loud). In addition, she also sang the same triad pattern in four different styles of singing, classical, pop, jazz, and blues, in the same three loudness conditions. A panel of experts rated the degree of perceived phonatory press along visual analogue scales. Comparing the obtained mean rated pressedness ratings with the mean NAQ values for the various triads showed that about 73% of the variation in perceived pressedness could be accounted for by variations of NAQ.     

Preliminary evaluation of selected acoustic and glottographic measures for clinical phonatory function analysis

Acoustic and glottographic measures may provide important information that could enhance clinical management and documentation of vocal dysfunction. Acoustic measures such as jitter and shimmer reflect “short-term” perturbations, or instabilities of the voice, and the coefficients of variation for frequency and for amplitude reflect “long-term” perturbations. Interpretations of these acoustic measures are based on the assumption that vocal perturbations may be related to laryngeal tissue abnormalities, asymmetries in vocal fold movement, or neuromuscular fluctuations in the respiratory, laryngeal, or vocal tract systems. The abduction quotient is a glottographic measure related to laryngeal adduction and is obtained from an analysis of the electroglottograph signal. The adduction measure appears to be independent of the acoustic perturbation measures. Interpretations of the acoustic and adductory measures may, therefore, complement each other for greater understanding of a patient's laryngeal behavior. Visual displays of the acoustic and glottographic signals also are discussed to demonstrate their value in voice signal interpretations. Case studies illustrate potential interpretations of the acoustic perturbation and abduction quotient measures.     

Voice source characteristics in six premier country singers

Voice source characteristics as derived from inverse filtering were analyzed in 6 country singers' speech and singing. Results showed that the closed quotient varied systematically with vocal loudness, and that glottal compliance (the ratio between transglottal AC volume displacement and subglottal pressure) decreased with increases in fundamental frequency but remained unaffected by vocal loudness. No striking differences were found in source characteristics between speech and singing within subjects. The degree of phonatory press, as judged by a panel of 19 expert listeners, appeared related to the range in which the singer was singing and to the sound pressure level gain from a doubling of subglottal pressure.     

Dependence of jaw opening on pitch and vowel in singers

In singing, F₀ sometimes is much higher than the typical frequency value of F₁. According to previous investigations, sopranos raise F₁ to a frequency near F₀ by widening the jaw opening in such cases. In the present study, the jaw opening was measured in 10 professional singers of different categorizations whose task was to sing an ascending two-octave scale on different vowels. Their normal F₁ values for these vowels were determined at a low F₀. Only for the vowels /a/ and /a/ did the singers widen the jaw opening when F₀ approached the F₁ value measured at a low pitch. For the other vowels, jaw opening was widened, beginning at a higher F₀. It is assumed that for these vowels the singers used other articulatory means to increase F₁.     

Breathing muscle activity and subglottal pressure dynamics in singing and speech

Previous studies have indicated that the diaphragm may contribute to the accomplishment of the quick and precise subglottal pressure changes required during singing. The present investigation compares data collected from simultaneously recorded electromyograms from breathing muscles and transdiaphragmatic pressure during singing as well as during nonsense and emphatic speech.     

Phonational profiles of female professional singers and nonsingers

Measures of the SFF, vocal intensity, phonational range, and habitualpitch level are reported for 39 professional singer and 39 nonsinger females, who were divided into three age groups (young, middle, and old age), with the professionals further divided into sopranos and altos. Each read the “Rainbow Passage” and spoke extemporaneously, from which measures of the SFF and vocal intensity were calculated; phonational range and habitual pitch levels were also determined. No significant differences were noted between the reading and speaking tasks. The SFF and intensity levels were significantly higher for the professionals in comparison to the nonsingers, but only for certain age groups. Moreover, whereas the nonsinger SFF levels varied significantly as a function of age, those for the professional singers did not. Although trends occurred, no significant differences were found for the mean phonational range or habitual pitch levels when the professionals and nonsingers were compared.     

Development of an Auditory-Perceptual Rating Instrument for the Operatic Singing Voice

Although considerable progress has been made in the development of acoustic and physiological measures of operatic singing voice, there is still no widely accepted objective tool for the evaluation of its multidimensional features. Auditory-perceptual evaluation, therefore, remains an important evaluation method for singing pedagogues, voice scientists, and clinicians who work with opera singers. Few investigators, however, have attempted to develop standard auditory-perceptual tools for evaluation of the operatic voice. This study aimed to pilot test a new auditory-perceptual rating instrument for operatic singing voice. Nine expert teachers of operatic singing used the instrument to rate the singing voices of 21 professional opera chorus artists from a national opera company. The findings showed that the instrument has good face validity, that it can be legitimately treated as a psychometrically sound scale, and that raters can use the scale consistently, both between and within judges. This new instrument, therefore, has the potential to allow opera singers, their teachers, voice care clinicians, and researchers to evaluate the important auditory-perceptual features of operatic voice quality.     

Self-reported voice problems among three groups of professional singers

A vocal health questionnaire was administered to three groups of professional singers and a “friendship-matched” group of nonsingers in Melbourne, Australia. The responses of 79 opera, 57 musical theatre and 31 contemporary (excluding rock) singers and 86 nonsingers were analysed. The questionnaire solicited information regarding biographical data speaking and singing voice-use behaviours, and vocal health over the previous 12 months in terms of experiences of vocal impairment, vocal disability, and handicap. Significant differences between singers and nonsingers in the prevalence and nature of voice problems were reported. Of the singers, 44% reported one or more occurrences of a diagnosed vocal condition compared to 21% of nonsingers and 69% of singers experienced vocal disability compared to only 41% of nonsingers, over the previous 12 months. In contrast, no significant differences were found between the three different styles of singers in their experience of vocal impairment, disability or handicap.     

Spectrum effects of subglottal pressure variation in professional baritone singers

The audio signal from five professional baritones was analyzed by means of spectrum analysis. Each subject sang syllables [pae] and [pa] from loudest to softest phonation at fundamental frequencies representing 25%, 50%, and 75% of his total range. Ten subglottal pressures, equidistantly spaced between highest and lowest, were selected for analysis along with the corresponding production of the vowels. The levels of the first formant and singer's formant were measured as a function of subglottal pressure. Averaged across subjects, vowels, and F0, a 10-dB increase at 600 Hz was accompanied by a 16-dB increase at 3 kHz.     

The membranous contact quotient: A new phonatory measure of glottal competence

The membranous contact quotient (MCQ) is introduced as a measure of dynamic glottal competence. It is defined as the ratio of the membranous contact glottis (the anterior-posterior length of contact between the two membranous vocal folds) and the membranous vocal fold length. An elliptical approximation to the vocal fold contour during phonation was used to predict MCQ values as a function of vocal process gap (adduction), maximum glottal width, and membranous glottal length. MCQ is highly dependent on the vocal process gap and the maximum glottal width, but not on vocal fold length. Five excised larynges were used to obtain MCQ data for a wide range of vocal process gaps and maximum glottal widths. Predicted and measured MCQ values had a correlation of 0.93, with an average absolute difference of 9.6% (SD = 10.5%). The model is better at higher values of MCQ. The theory for MCQ is also expressed as a function of vocal process gap and subglottal pressure to suggest production control potential. The MCQ measure is obtainable with the use of stroboscopy and appears to be a potentially useful clinical measure.     

Effects of lung volume on vertical larynx position during phonation

The vertical position of the larynx seems to be relevant to voicefunction. As a high vertical larynx position is often seen in hyperfunctional and strained voices, a lowering of a habitually elevated larynx is sometimes a specific goal in clinical voice therapy and different larynx-lowering exercises are used to achieve this goal. Earlier investigations have shown that pitch and to some extent also vocal loudness are relevant to vertical larynx position. In the present investigation, we examine if lung volume affects vertical larynx position. Using a multi-channel electroglottograph, the larynx position was measured in 29 healthy, vocally untrained subjects, who phonated at different lung volumes, pitches, and degrees of vocal loudness. The main results were that high lung volume was clearly associated with a lower larynx position as compared to low lung volume. In addition, vertical larynx position was strongly correlated with pitch. Both of these dependencies were shown to be stronger in males than in females. Our results suggest that lung volume is a factor that is highly relevant to larynx height in untrained subjects.     

Respiratory function during speaking and singing in professional country singers

Respiratory function during speaking and singing was investigated in six male professional country singers. Function was studied using magnetometers to transduce anteroposterior diameter changes of the rib cage and abdomen while subjects performed various respiratory maneuvers, speaking activities, and singing activities. Results indicated that respiratory behavior during speaking was generally the same as that of other normal subjects. Respiratory behavior during singing resembled that of speaking. Discussion includes comparison of respiratory performance of present singers with untrained singers and classically trained singers. Implications are offered regarding how the results might be applied to the prevention of voice disorders by education and training of country singers.     

Effects of Inhalatory Abdominal Wall Movement on Vertical Laryngeal Position During Phonation

The configuration of the body resulting from inhalatory behavior is sometimes considered a factor of relevance to voice production in singing and speaking pedagogy and in clinical voice therapy. The present investigation compares two different inhalatory behaviors: (1) with a "paradoxical" inward movement of the abdominal wall, and (2) with an expansion of the abdominal wall, both with regard to the effect on vertical laryngeal position during the subsequent phonation. Seventeen male and 17 female healthy, vocally untrained subjects participated. No instructions were given regarding movements of the rib cage. Inhaled air volume as measured by respiratory inductive plethysmography, was controlled to reach 70% inspiratory capacity. Vertical laryngeal position was recorded by two-channel electroglottography during the subsequent vowel production. A significant effect was found; the abdomen-out condition was associated with a higher laryngeal position than the abdomen-in condition. This result apparently contradicted a hypothesis that an expansion of the abdominal wall would allow the diaphragm to descend deeper in the torso, thereby increasing the tracheal pull, which would result in a lower laryngeal position. In a post-hoc experiment including 6 of the subjects, body posture was studied by digital video recordings, revealing that the two inhalatory modes were clearly associated with postural changes affecting laryngeal position. The "paradoxical" inward movement of the abdominal wall was associated with a recession of the chin toward the neck, such that the larynx appeared in a lower position in the neck, for reasons of a postural change. The results suggest that the laryngeal position can be affected by the inhalatory behavior if no attention is paid to posture, implying that instructions from clinicians and pedagogues regarding breathing behavior must be carefully formulated and adjusted in order to ensure that the intended goals are reached.     

Comparisons of pharynx, source, formant, and pressure characteristics in operatic and musical theatre singing

Belting, a vocal technique typically cultivated in musical theatre singing, differs timbrally from operatic singing in many interesting respects. The underlying phonatory differences have not been previously investigated in detail. Yet, belting is frequently associated with disturbances of voice function. Articulatory and phonatory characteristics are investigated in a female subject who is a professional singer (co-author JL) trained in both the operatic and belting styles and in an intermediate vocal technique (“mixed”). This article presents data obtained from this subject by video-fiberoptic observation of the pharynx, inverse filtering of airflow, and measurement of subglottal pressure. The results reveal that belting was characterized by very high subglottal pressures and sound levels, and apparently also by a comparatively high degree of glottal adduction. Comparisons with other investigations of related aspects of belting and operatic singing support the assumption that the data obtained from our subject are representative for these vocal techniques.     

Respiratory and glottal efficiency measures in normal classically trained singers

Respiratory and glottal efficiency measures were collected from a pool of 40 classically trained singers with normal larynges. All singers had ?3 years of formal classical voice training and were active professional solo classical singers. Mean flow rates were obtained from all subjects to assess glottal efficiency. Additionally, maximum phonation times and phonation quotients were obtained from a subset of the singers. Pulmonary function test data on forced expiratory volume, forced vital capacity, and forced expiratory flow were obtained for all subjects. Results were compared with published normal values, not specifically derived from trained singers, used commonly in voice laboratoires. Differences were found, suggesting the need for separate normative data to be used for evaluation of the vocal athlete.     

Vocalization and breathing during the second and third years of life

Vocalization and breathing were studied in 40 healthy young children,including 5 boys and 5 girls at each, of ages of 18, 24, 30, and 36 months. A variable inductance plethysmograph was used to obtain estimates of volume changes of the rib cage, abdomen, and lung, as well as estimates of selected temporal features of the breathing cycle. Results indicated that breathing behavior was influenced by height and age, but not by vocalization type or sex. Such behavior was found to be highly variable, demonstrating that these young children had multiple degrees of freedom of performance available to accomplish the aeromechanical drive required.