Blend in Singing Ensemble Performance: Vibrato Production in a Vocal Quartet

OBJECTIVES

"Blend" is a defining characteristic of good vocal ensemble performance. To achieve this, directors often consider vibrato as a feature to be controlled and consequently restrict its use. Analysis of individual voices in ensemble situations presents several challenges, including the isolation of voices for analysis from recordings. This study considers vibrato production as a feature that contributes to blend through an ecological study of a vocal quartet.

METHODS

A vocal ensemble was recorded using head-worn microphones and electrolaryngograph electrodes to enable fundamental frequency analysis of the individual voices. The same four-part material was recorded over several weeks of rehearsal to allow analysis of conscious and subconscious changes to vibrato production over time. Alongside the recording of their rehearsal discussions, singers were also asked for opinions on vibrato production in connection with blend.

RESULTS AND CONCLUSIONS

The results indicate that vibrato is adjusted to some extent by individual singers to improve blend, with some instances of synchrony between voice parts. Some conscious alterations to vibrato were made to improve blend; however, these are not always evident in the data, suggesting that singers' own perceptions of their performance may be influenced by other factors. These findings indicate a need for further studies of vibrato as a feature of blend, particularly in terms of the synergies between expectation and actual production, and potential synchronicity between singers; increased understanding of vibrato in an ensemble setting will lead to more efficient rehearsal techniques and vocal training, and could prevent vocal misuse leading to pathology in the future.

Audience gaze while appreciating a multipart musical performance

Visual information has been observed to be crucial for audience members during musical performances. The present study used an eye tracker to investigate audience members' gazes while appreciating an audiovisual musical ensemble performance, based on evidence of the dominance of musical part in auditory attention when listening to multipart music that contains different melody lines and the joint-attention theory of gaze. We presented singing performances, by a female duo. The main findings were as follows: (1) the melody part (soprano) attracted more visual attention than the accompaniment part (alto) throughout the piece, (2) joint attention emerged when the singers shifted their gazes toward their co-performer, suggesting that inter-performer gazing interactions that play a spotlight role mediated performer-audience visual interaction, and (3) musical part (melody or accompaniment) strongly influenced the total duration of gazes among audiences, while the spotlight effect of gaze was limited to just after the singers' gaze shifts.

Sing Your Lungs Out: a qualitative study of a community singing group for people with chronic obstructive pulmonary disease (COPD)

OBJECTIVE

To explore the ways in which participation in a community singing group contributed to the health and well-being of patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Qualitative description, based on transcripts from individual interviews and a focus group meeting with people with COPD participating in the singing group, regarding their experience.

SETTING

Urban community, Wellington, New Zealand.

PARTICIPANTS

23 people (13 women and 10 men), 51-91 years with COPD (21) or interstitial lung disease (2).

RESULTS

The weekly singing group was a well-attended activity, with self-reported benefits to health and well-being. 4 key themes were identified: being in the 'right space', connection, purpose and growth, and participation in a meaningful physical activity.

CONCLUSIONS

This study helps us to better understand how participation in a community singing group can benefit the health and well-being of patients with COPD.

TRIAL REGISTRATION NUMBER

ACTRN12615000736549; Results.

Temporal variability in sung productions of adolescents who stutter

Singing has long been used as a technique to enhance and reeducate temporal aspects of articulation in speech disorders. In the present study, differences in temporal structure of sung versus spoken speech were investigated in stuttering. In particular, the question was examined if singing helps to reduce VOT variability of voiceless plosives, which would indicate enhanced temporal coordination of oral and laryngeal processes. Eight German adolescents who stutter and eight typically fluent peers repeatedly spoke and sang a simple German congratulation formula in which a disyllabic target word (e.g., /'ki:ta/) was repeated five times. Every trial, the first syllable of the word was varied starting equally often with one of the three voiceless German stops /p/, /t/, /k/. Acoustic analyses showed that mean VOT and stop gap duration reduced during singing compared to speaking while mean vowel and utterance duration was prolonged in singing in both groups. Importantly, adolescents who stutter significantly reduced VOT variability (measured as the Coefficient of Variation) during sung productions compared to speaking in word-initial stressed positions while the control group showed a slight increase in VOT variability. However, in unstressed syllables, VOT variability increased in both adolescents who do and do not stutter from speech to song. In addition, vowel and utterance durational variability decreased in both groups, yet, adolescents who stutter were still more variable in utterance duration independent of the form of vocalization. These findings shed new light on how singing alters temporal structure and in particular, the coordination of laryngeal-oral timing in stuttering. Future perspectives for investigating how rhythmic aspects could aid the management of fluent speech in stuttering are discussed.

LEARNING OUTCOMES

Readers will be able to describe (1) current perspectives on singing and its effects on articulation and fluency in stuttering and (2) acoustic parameters such as VOT variability which indicate the efficiency of control and coordination of laryngeal-oral movements. They will understand and be able to discuss (3) how singing reduces temporal variability in the productions of adolescents who do and do not stutter and 4) how this is linked to altered articulatory patterns in singing as well as to its rhythmic structure.

The perceived effects of singing on the health and well-being of wives and partners of members of the British Armed Forces: a cross-sectional survey

OBJECTIVES

A survey to explore the extent to which a choir programme associated with the British Armed Forces provides benefits of wives and partners and families of military personnel.

STUDY DESIGN

A cross-sectional survey.

METHOD

Online self-completion questionnaires to survey 464 choir members and 173 committee members who were also participants in the choirs.

RESULTS

Large majorities of participants report personal and social benefits from their engagement in choirs, as well as benefits for their health and well-being. Challenges facing choirs were also identified associated with performance demands and inter-personal relationships within choirs.

CONCLUSIONS

Group singing generates a range of personal, social and health benefits for wives and partners of armed services personnel. The study reveals some challenges arising in all-female choirs in military settings and suggests potential areas for further research.

Neural activity related to discrimination and vocal production of consonant and dissonant musical intervals

BACKGROUND

Relationships between musical pitches are described as either consonant, when associated with a pleasant and harmonious sensation, or dissonant, when associated with an inharmonious feeling. The accurate singing of musical intervals requires communication between auditory feedback processing and vocal motor control (i.e. audio-vocal integration) to ensure that each note is produced correctly. The objective of this study is to investigate the neural mechanisms through which trained musicians produce consonant and dissonant intervals.

METHODOLOGY

We utilized 4 musical intervals (specifically, an octave, a major seventh, a fifth, and a tritone) as the main stimuli for auditory discrimination testing, and we used the same interval tasks to assess vocal accuracy in a group of musicians (11 subjects, all female vocal students at conservatory level). The intervals were chosen so as to test for differences in recognition and production of consonant and dissonant intervals, as well as narrow and wide intervals. The subjects were studied using fMRI during performance of the interval tasks; the control condition consisted of passive listening.

RESULTS

Singing dissonant intervals as opposed to singing consonant intervals led to an increase in activation in several regions, most notably the primary auditory cortex, the primary somatosensory cortex, the amygdala, the left putamen, and the right insula. Singing wide intervals as opposed to singing narrow intervals resulted in the activation of the right anterior insula. Moreover, we also observed a correlation between singing in tune and brain activity in the premotor cortex, and a positive correlation between training and activation of primary somatosensory cortex, primary motor cortex, and premotor cortex during singing. When singing dissonant intervals, a higher degree of training correlated with the right thalamus and the left putamen.

CONCLUSIONS/SIGNIFICANCE

Our results indicate that singing dissonant intervals requires greater involvement of neural mechanisms associated with integrating external feedback from auditory and sensorimotor systems than singing consonant intervals, and it would then seem likely that dissonant intervals are intoned by adjusting the neural mechanisms used for the production of consonant intervals. Singing wide intervals requires a greater degree of control than singing narrow intervals, as it involves neural mechanisms which again involve the integration of internal and external feedback.

Word Intelligibility in Multi-voice Singing: The Influence of Chorus Size

OBJECTIVE

This study investigated how the intelligibility of sung words is influenced by the number of singers in a choral music style.

METHODS

The study used repeated measures factorial. One hundred forty-nine participants listened to recordings of spoken and sung English words and attempted to identify the words. Each stimuli word was sung or spoken in sync by either one, four, eight, sixteen, or twenty-seven members of a high-quality Soprano Alto Tenor Bass (SATB) choir.

RESULTS

In general, single-voice word recognition was higher than multi-voice word recognition in the sung condition. However, the difference between four concurrent singers and the full choir was negligible; that is, reduced intelligibility with multiple singers shows little sensitivity to the number of singers. The principal effect of voice density on intelligibility is found to occur with coda consonants-a result consistent with the importance many choral conductors attribute to coordinating word offsets. In particular, the plosives /b/, /d/, /g/, and /p/ are easily confused. Coda liquids (/l/,/r/) were also found to be a source of confusion. Finally, an increasing density of voices appears to have a facilitating effect for the coda nasal /m/.

CONCLUSIONS

Groups of four or more choral singers do appear to be less intelligible than single singers, although the observed effect is modest. However, increasing the number of singers in a choral texture beyond four singers does not appear to further degrade intelligibility.

Resonance Tuning in Three Girl Choristers

OBJECTIVE

The phenomenon of resonance tuning, whereby a singer modifies the shape of their vocal tract to increase the acoustic power output, is commonly exploited across large pitch ranges by professional sopranos and has been observed to a lesser degree in nonexpert adult singers. This study considers the employment of two common resonance tuning techniques in experienced child singers; tuning the first vocal tract resonance to the fundamental (R₁: f_o) and tuning the second resonance to the second harmonic (R₂:2 f_o).

METHODS

Wide-band excitation at the subject's mouth during singing was used to measure the vocal tract resonances of three girl choristers, and vowel formant values in speech were extracted from samples of spoken text. Measured resonance values were cross-referenced with first and second harmonics for sung vowels across the subjects' ranges to identify the resonance tuning techniques employed, and these results were compared with those previously observed by others in professional adult classical singers.

RESULTS AND CONCLUSIONS

There was clear evidence that the subjects employed resonance tuning techniques comparable with the strategies used by adult singers. The protocol and results presented here pave the way for further studies exploring the development of resonance tuning techniques in young soprano voices, with the potential to impact on approaches to classical singing training in the future.

Interactive Augmentation of Voice Quality and Reduction of Breath Airflow in the Soprano Voice

In 1985, at a conference sponsored by the National Institutes of Health, Martin Rothenberg first described a form of nonlinear source-tract acoustic interaction mechanism by which some sopranos, singing in their high range, can use to reduce the total airflow, to allow holding the note longer, and simultaneously enrich the quality of the voice, without straining the voice. (M. Rothenberg, "Source-Tract Acoustic Interaction in the Soprano Voice and Implications for Vocal Efficiency," Fourth International Conference on Vocal Fold Physiology, New Haven, Connecticut, June 3-6, 1985.) In this paper, we describe additional evidence for this type of nonlinear source-tract interaction in some soprano singing and describe an analogous interaction phenomenon in communication engineering. We also present some implications for voice research and pedagogy.

Semioccluded Vocal Tract Exercises: Changes in Laryngeal and Pharyngeal Activity During Stroboscopy

OBJECTIVE

The purpose of this study was to compare the changes in laryngeal activity from baseline during three different semioccluded vocal tract exercises (SOVTs).

STUDY DESIGN

This is a prospective case-series study.

METHODS

Transnasal stroboscopy was performed while four singers performed three SOVTs (straw phonation, lip trill, and tongue trill) to evaluate laryngeal changes during the execution of SOVTs. Evaluations using a modified Stroboscopy Evaluation Rating Form captured the following parameters: amplitude of vocal fold movement, mucosal wave, phase closure, glottal closure, anterior-posterior vocal tract constrictions, medial-lateral vocal tract constrictions, laryngeal ascension, and pharyngeal constriction during a pitch glide.

RESULTS

The parameters that changed from baseline, as well as the direction and magnitude of change that occurred across SOVTs, varied within and between each subject. All the singers benefited from at least one SOVT, but no single SOVT benefited all four singers.

CONCLUSIONS

Although SOVTs result in endoscopic and stroboscopic changes that might be considered beneficial, the results indicate marked variability across SOVTs and singers in terms of the laryngeal and pharyngeal adjustments induced by the exercises. Singing teachers and Speech Language Pathologists (SLPs) may need to more carefully assess the impact of specific SOVTs when deciding which one(s) to prescribe as a teaching or therapeutic exercise.

The Measurement of Airflow Using Singing Helmet That Allows Free Movement of the Jaw

OBJECTIVES

Airflow measurement is a useful method of evaluating laryngeal physiology. We introduce a noninvasive device that measures airflow without restricting jaw movement or requiring phonation into a mouthpiece, thus facilitating measurement during singing and connected speech.

STUDY DESIGN

Validation and human subject trials were conducted. Airflow measurements were obtained from 16 male and 16 female subjects during singing, speech, and constant vowel production tasks.

METHODS

A similar helmet was designed by Stevens and Mead in 1968. The new device validity was evaluated by comparing the measured volume of air to a known volume of administered air using a calibration syringe. Subjects were asked to voice sustained vowels at low, medium, and high vocal intensity, read two sentences at a conversational volume, and perform different singing exercises while airflow was recorded.

RESULTS

The device accurately and reliably measured airflow with mean airflow values falling within previously published ranges. There was an experimentally determined response time of 0.173 ± 0.014 seconds. Subjects were able to comfortably perform speech and singing exercises. Male subjects had higher airflow for all sustained vowels (P < 0.05). Airflow was higher for abduction rather than adduction sentences (P < 0.05).

CONCLUSIONS

No other portable device has been shown to measure airflow during singing and speech while allowing for free movement of the jaw. This device provides a more natural environment to measure airflow that could be used to help evaluate laryngeal function and aid in singing training.

Glottal Adduction and Subglottal Pressure in Singing

Previous research suggests that independent variation of vocal loudness and glottal configuration (type and degree of vocal fold adduction) does not occur in untrained speech production. This study investigated whether these factors can be varied independently in trained singing and how subglottal pressure is related to average glottal airflow, voice source properties, and sound level under these conditions. A classically trained baritone produced sustained phonations on the endoscopic vowel [i:] at pitch D4 (approximately 294 Hz), exclusively varying either (a) vocal register; (b) phonation type (from "breathy" to "pressed" via cartilaginous adduction); or (c) vocal loudness, while keeping the others constant. Phonation was documented by simultaneous recording of videokymographic, electroglottographic, airflow and voice source data, and by percutaneous measurement of relative subglottal pressure. Register shifts were clearly marked in the electroglottographic wavegram display. Compared with chest register, falsetto was produced with greater pulse amplitude of the glottal flow, H1-H2, mean airflow, and with lower maximum flow declination rate (MFDR), subglottal pressure, and sound pressure. Shifts of phonation type (breathy/flow/neutral/pressed) induced comparable systematic changes. Increase of vocal loudness resulted in increased subglottal pressure, average flow, sound pressure, MFDR, glottal flow pulse amplitude, and H1-H2. When changing either vocal register or phonation type, subglottal pressure and mean airflow showed an inverse relationship, that is, variation of glottal flow resistance. The direct relation between subglottal pressure and airflow when varying only vocal loudness demonstrated independent control of vocal loudness and glottal configuration. Achieving such independent control of phonatory control parameters would be an important target in vocal pedagogy and in voice therapy.

Performing Lieder: Expert Perspectives and Comparison of Vibrato and Singer's Formant With Opera Singers

This article reports three studies about performance of lieder, and in particular in comparison with opera performance. In study 1, 21 participants with experience in music performance and teaching completed a survey concerning various characteristics of lieder performance. The results showed that there was consensus between the literature and the assessment of an expert panel-that a "natural" and "unoperatic" vibrato was favored, and that diction, text, and variation of tone are all important aspects of lieder performance. Two acoustic analyses were conducted to investigate genre-specific differences of the singer's formant and vibrato parameters. The first analysis (study 2) used 18 single quasi-unaccompanied notes from commercial recordings of two lieder, and, for comparison, 20 single unaccompanied notes from an opera. Vibrato rate was statistically identical between the two genres at ~6.4 Hz; however, lieder featured a longer delay in vibrato onset. Vibrato extent was smaller for lieder (~112 cents) compared with opera (~138 cents). The singer's formant, which is generally associated with opera, was at times observed in the lieder recordings; however, this was at an overall significantly weaker intensity than in the opera recordings. The results were replicated in study 3, where recordings using only singers who performed in both lied and opera were analyzed. This direct comparison used 45 lieder notes and 55 opera notes and also investigated three different methods of analyzing the singer's formant. A number of consistencies and inconsistencies were identified between acoustic parameters reported in studies 2 and 3, and the beliefs of singing teachers and scholars in the literature and study 1.

The effects of emotional expression on vibrato

OBJECTIVES/HYPOTHESIS

The purpose of this study was to investigate the effect of emotional expression on several acoustic measures of vibrato, including its rate, extent, and steadiness. We hypothesized that singing a passage with emotional content would influence these variables.

STUDY DESIGN

This study used a within-subjects, repeated-measures design. Singer performance under different conditions was analyzed.

METHODS

Ten graduate student singers (eight women, two men) completed a series of tasks including sustained sung vowels at several pitch and loudness levels, an assigned song that was judged to have relatively neutral emotion, and a personal selection that included passages of intense emotion. Vowel tokens were extracted from the recordings and averaged for each task. Dependent measures included the mean fundamental frequency (F0), mean intensity, frequency modulation (FM) rate, FM extent, and measures of FM rate and extent variability.

RESULTS

The FM rate and extent were higher and the modulation variability was lower for the more emotional song than for the sustained vowels. Mean F0 and intensity were higher for the emotional song than for the neutral song.

CONCLUSIONS

Singing an emotional passage influences acoustic features of vibrato when compared with isolated, sustained vowels. The wider dynamic and pitch ranges for emotional passages only partly explain vibrato differences between emotional and neutral singing.

Common cues to emotion in the dynamic facial expressions of speech and song

Speech and song are universal forms of vocalization that may share aspects of emotional expression. Research has focused on parallels in acoustic features, overlooking facial cues to emotion. In three experiments, we compared moving facial expressions in speech and song. In Experiment 1, vocalists spoke and sang statements each with five emotions. Vocalists exhibited emotion-dependent movements of the eyebrows and lip corners that transcended speech–song differences. Vocalists’ jaw movements were coupled to their acoustic intensity, exhibiting differences across emotion and speech–song. Vocalists’ emotional movements extended beyond vocal sound to include large sustained expressions, suggesting a communicative function. In Experiment 2, viewers judged silent videos of vocalists’ facial expressions prior to, during, and following vocalization. Emotional intentions were identified accurately for movements during and after vocalization, suggesting that these movements support the acoustic message. Experiment 3 compared emotional identification in voice-only, face-only, and face-and-voice recordings. Emotion judgements for voice-only singing were poorly identified, yet were accurate for all other conditions, confirming that facial expressions conveyed emotion more accurately than the voice in song, yet were equivalent in speech. Collectively, these findings highlight broad commonalities in the facial cues to emotion in speech and song, yet highlight differences in perception and acoustic-motor production.

Intelligibility of sung vowels: the effect of consonantal context and the onset of voicing

BACKGROUND

Studies addressing the identification of sung vowels concern mainly the effect of the fundamental frequency (f0) and conclude that correct vowel identification decreases with increasing pitch. In one experiment, the impact of consonantal environment on the intelligibility of the vowels in high-pitched singing was also studied. The results of that experiment showed positive effect of the consonantal environment. This finding is in line with results that had been reported for speech in an earlier study. However, the data on singing are not as transparent as the authors suggest, and there are some conditions in the experiment that could also be controlled for more strictly. Therefore, the effect of the dynamic acoustic information encoded in the formant transitions at high fundamental frequencies is still an open question.

OBJECTIVES

The aim of the present study was to redesign and extend the above-mentioned experiment to test whether the phonetic context and the onset of the vowel uttered in isolation (namely the onset of voicing) have a positive effect on vowel identification.

METHODS

For this purpose, a vowel identification test was carried out. The stimuli included three Hungarian vowels /aː iː uː/ in three conditions (in /bVb/ context, in isolation and with eliminated onset) at seven different fundamental frequencies from 175 to 988 Hz (F3, B3, F4, B4, F5, B5, and speech). The stimuli were produced by one professional soprano singer.

RESULTS

The results show that consonantal context does not specify vowel identity in singing as clearly as it has been demonstrated for spoken utterances. In addition, no effect of vowel onset (ie, the onset of voicing) was found. Recognition percentages seemed only to be dependent on f0 and vowel quality.

CONCLUSIONS

The unexpected results lend themselves to two possible explanations: the reduction of the consonants and the undersampling of the formant transitions.

The effect of singing training on voice quality for people with quadriplegia

OBJECTIVES

Despite anecdotal reports of voice impairment in quadriplegia, the exact nature of these impairments is not well described in the literature. This article details objective and subjective voice assessments for people with quadriplegia at baseline and after a respiratory-targeted singing intervention.

STUDY DESIGN

Randomized controlled trial.

METHODS

Twenty-four participants with quadriplegia were randomly assigned to a 12-week program of either a singing intervention or active music therapy control. Recordings of singing and speech were made at baseline, 6 weeks, 12 weeks, and 6 months postintervention. These deidentified recordings were used to measure sound pressure levels and assess voice quality using the Multidimensional Voice Profile and the Perceptual Voice Profile.

RESULTS

Baseline voice quality data indicated deviation from normality in the areas of breathiness, strain, and roughness. A greater percentage of intervention participants moved toward more normal voice quality in terms of jitter, shimmer, and noise-to-harmonic ratio; however, the improvements failed to achieve statistical significance.

CONCLUSIONS

Subjective and objective assessments of voice quality indicate that quadriplegia may have a detrimental effect on voice quality; in particular, causing a perception of roughness and breathiness in the voice. The results of this study suggest that singing training may have a role in ameliorating these voice impairments.