Effect of Hydration and Vocal Rest on the Vocal Fatigue in Amateur Karaoke Singers

Karaoke singing is a very popular entertainment among young people in Asia. It is a leisure singing activity with the singer's voice amplified with special acoustic effects in the backdrop of music. Music video and song captions are shown on television screen to remind the singers during singing. It is not uncommon to find participants singing continuously for four to five hours each time. As most of the karaoke singers have no formal training in singing, these amateur singers are more vulnerable to developing voice problems under these intensive singing activities. This study reports the performance of 20 young amateur singers (10 males and 10 females, aged between 20-25 years) on a series of phonatory function tasks carried out during continuous karaoke singing. Half of the singers were given water to drink and short duration of vocal rests at regular intervals during singing and the other half sang continuously without taking any water or rest. The subjects who were given hydration and vocal rests sang significantly longer than those who did not take any water or rest. The voice quality, as measured by perceptual and acoustic measures, and vocal function, as measured by phonetogram, did not show any significant changes during singing in the subjects who were given water and rest during the singing. However, subjects who sang continuously without drinking water and taking rests showed significant changes in the jitter measure and the highest pitch they could produce during singing. These results suggest that hydration and vocal rests are useful strategies to preserve voice function and quality during karaoke singing. This information is useful educational information for karaoke singers.     

Significance of Auditory and Kinesthetic Feedback to Singers'' Pitch Control

An accurate control of fundamental frequency (F0) is required from singers. This control relies on auditory and kinesthetic feedback. However, a loud accompaniment may mask the auditory feedback, leaving the singers to rely on kinesthetic feedback. The object of the present study was to estimate the significance of auditory and kinesthetic feedback to pitch control in 28 students beginning a professional solo singing education. The singers sang an ascending and descending triad pattern covering their entire pitch range with and without masking noise in legato and staccato and in a slow and a fast tempo. F0 was measured by means of a computer program. The interval sizes between adjacent tones were determined and their departures from equally tempered tuning were calculated. The deviations from this tuning were used as a measure of the accuracy of intonation. Statistical analysis showed a significant effect of masking that amounted to a mean impairment of pitch accuracy by 14 cent across all subjects. Furthermore, significant effects were found of tempo as well as of the staccato/legato conditions. The results indicate that auditory feedback contributes significantly to singers' control of pitch.     

Effects of a professional solo singer education on auditory and kinesthetic feedback—a longitudinal study of singers'' pitch control

The significance of auditory and kinesthetic feedback to pitch control in singing was described in a previous report of this project for students at the beginning of their professional solo singer education.(1) As it seems reasonable to assume that pitch control can be improved by training, the same students were reinvestigated after 3 years of professional singing education. As in the previous study, the singers sang an ascending and descending triad pattern with and without masking noise in legato and staccato and in a slow and a fast tempo. Fundamental frequency and interval sizes between adjacent tones were determined and compared with their equivalents in the equally tempered tuning. The average deviations from these values were used as estimates of intonation accuracy. Intonation accuracy was reduced by masking noise, by staccato as opposed to legato singing, and by fast as opposed to slow performance. The contribution of the auditory feedback to pitch control was not significantly improved after education, whereas the kinesthetic feedback circuit was improved in slow legato and slow staccato tasks. The results support the assumption that the kinesthetic feedback contributes substantially to intonation accuracy.     

Vowel Intelligibility in Classical Singing

Vowel intelligibility during singing is an important aspect of communication during performance. The intelligibility of isolated vowels sung by Western classically trained singers has been found to be relatively low, in fact, decreasing as pitch rises, and it is lower for women than for men. The lack of contextual cues significantly deteriorates vowel intelligibility. It was postulated in this study that the reduced intelligibility of isolated sung vowels may be partly from the vowels used by the singers in their daily vocalises. More specifically, if classically trained singers sang only a few American English vowels during their vocalises, their intelligibility for American English vowels would be less than for those classically trained singers who usually vocalize on most American English vowels. In this study, there were 21 subjects (15 women, 6 men), all Western classically trained performers as well as teachers of classical singing. They sang 11 words containing 11 different American English vowels, singing on two pitches a musical fifth apart. Subjects were divided into two groups, those who normally vocalize on 4, 5, or 6 vowels, and those who sing all 11 vowels during their daily vocalises. The sung words were cropped to isolate the vowels, and listening tapes were created. Two listening groups, four singing teachers and five speech-language pathologists, were asked to identify the vowels intended by the singers. Results suggest that singing fewer vowels during daily vocalises does not decrease intelligibility compared with singing the 11 American English vowels. Also, in general, vowel intelligibility was lower with the higher pitch, and vowels sung by the women were less intelligible than those sung by the men. Identification accuracy was about the same for the singing teacher listeners and the speech-language pathologist listeners except for the lower pitch, where the singing teachers were more accurate.     

Evaluation of Support in Singing

This study searched for perceptual, acoustic, and physiological correlates of support in singing. Seven trained professional singers (four women and three men) sang repetitions of the syllable [pa:] at varying pitch and sound levels (1) habitually (with support) and (2) simulating singing without support. Estimate of subglottic pressure was obtained from oral pressure during [p]. Vocal fold vibration was registered with dual-channel electroglottography. Acoustic analyses were made on the recorded samples. All samples were also evaluated by the singers and other listeners, who were trained singers, singing students, and voice specialists without singing education (a total of 63 listeners). We rated both the overall voice quality and the amount of support. According to the results, it seemed impossible to observe any auditory differences between supported singing and good singing voice quality. The acoustic and physiological correlates of good voice quality in absolute values seem to be gender and task dependent, whereas the relative optimum seems to be reached at intermediate parameter values.     

Effects of Professional Singing Education on Vocal Vibrato—A Longitudinal Study

Vocal vibrato is regarded as one of the essential characteristics of voice quality in classical singing. Professional singers seem to develop vibrato automatically, without actively striving to acquire it. In this longitudinal investigation, the vocal vibrato of 22 singing students was examined at the beginning of and after 3 years of professional singing education. Subjects sang an ascending-descending triad pattern in slow tempo on vowel [a:] at a comfortable pitch level twice at soft (piano) and twice at medium (mezzoforte) loudness. The top note of the triad pattern was sustained for approximately 5s. The mean and the standard deviation (SD) of the vibrato rate were measured for this note. Results revealed that after 3 years of training, voices with vibrato slower than 5.2 Hz were found to have a faster vibrato, and voices with vibrato faster than 5.8 Hz were found to have a slower vibrato. Standard deviation of vibrato rate was higher in soft than in medium loudness, particularly before the education. Also high values of SD of vibrato rate, exceeding 0.65 Hz, had decreased after the education. These findings confirm that vibrato characteristics can be affected by singing education.     

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.     

Long-Term-Average Spectrum Characteristics of Country Singers During Speaking and Singing

Five premier male country singers involved in our previous studies spoke and sang the words of both the national anthem and a country song of their choice. Long-term-average spectra were made of the spoken and sung material of each singer. The spectral characteristics of county singers' speech and singing were similar. A prominent peak in the upper part of the spectrum, previously described as the "speaker's formant," was found in the county singers' speech and singing. The singer's formant, a strong spectral peak near 2.8 kHz, an important part of the spectrum of classically trained singers, was not found in the spectra of the country singers. The results support the conclusion that the resonance characteristics in speech and singing are similar in country singing and that county singing is not characterized by a singer's formant.     

Pitch Discrimination and Pitch Matching Abilities of Adults who Sing Inaccurately

Past research regarding singing ability has provided evidence that both supports and refutes a relationship between pitch discrimination ability and pitch production ability. Researchers have suggested that these skills improve with age. Despite this suggestion, most investigators studying singing ability have included only children as participants. Additionally, although many researchers have studied accurate singers, few have directly studied persons who do not sing accurately. We designed this study to examine the relationship between pitch discrimination ability and pitch production ability in inaccurate adult singers. Fifteen adults, aged 18 to 40 years, that met specific criteria qualified as inaccurate singers. Each participated in two tasks, a pitch discrimination task and a pitch production task. We used the Multi-Dimensional Voice Profile-Advanced (Kay Elemetrics Corporation, Lincoln Park, NJ) to determine the frequency of each participant's vocal productions during the pitch production task. We also used a Pearson product moment correlation to analyze the relationship between pitch discrimination and pitch production accuracy within a semitone of the target frequency. No meaningful relationship was found, and results were not statistically significant. However, the inaccurate singers in this study could be classified into two separate categories, those who discriminated pitches accurately, but produced pitches inaccurately, and those who discriminated pitches inaccurately and produced pitches inaccurately. These findings may be of great importance to music educators and impact the focus of instruction when teaching an inaccurate singer to sing more accurately.     

Estimated subglottal pressure in six professionalcountry singers

Estimates of subglottal pressure in six professional male country singerswere obtained during the /p/ occlusion while the subjects spoke, sang a country tune, and sang the tune of the United States national anthem. The subglottal pressure values, which were very similar in both the speech-like and singing-mode syllables, usually measured below 45 cm of water column, but they ranged as high as 59 cm. The sound pressure level in singing was also measured and was lower than that discovered in classically trained singers at high subglottal pressures.     

Perceptual and acoustic study of professionally trained versus untrained voices

Acoustic and perceptual analyses were completed to determine the effect of vocal training on professional singers when speaking and singing. Twenty professional singers and 20 nonsingers, acting as the control, were recorded while sustaining a vowel, reading a modified Rainbow Passage, and singing "America the Beautiful." Acoustic measures included fundamental frequency, duration, percent jitter, percent shimmer, noise-to-harmonic ratio, and determination of the presence or absence of both vibrato and the singer's formant. Results indicated that, whereas certain acoustic parameters differentiated singers from nonsingers within sex, no consistently significant trends were found across males and females for either speaking or singing. The most consistent differences were the presence or absence of the singer's vibrato and formant in the singers versus the nonsingers, respectively. Perceptual analysis indicated that singers could be correctly identified with greater frequency than by chance alone from their singing, but not their speaking utterances.     

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.     

The association between upper trapezius activity and thorax movement in classical singing

This study aimed to examine in classical singing the phasing of the activity in upper trapezius (TR) to upper and lower thorax movement and to the phasing of activity in the intercostals (INT) and in the lateral abdominal (OBL) muscles. Electromyographic (EMG) activity was recorded from the TR, INT, and OBL muscles on the right side. Thorax movement (TX) was traced with two strain gauge sensors placed around the upper and lower thorax. Four professional opera singers (soprano, mezzo, tenor, and baritone) and four advanced student classical singers (three sopranos and one mezzo) participated. Three of the professional singers were 33 years, and one was 40 years. The students were between 23 and 30 years. Different arias, freely chosen by the singers from their professional repertoire, served as the singing task for the opera singers. All students sang “Summertime” from Porgy and Bess. All subjects performed their task three times with variation in vocal loudness (normal, forte, piano). Thereafter, for all subjects, a biofeedback (BF) procedure was performed on TR to lower TR activity and a repeat performance of the singing tasks was carried out. EMG activity from the three recording sites and upper and lower TX circumference were compared before and after BF. A phasing of upper TR activity to INT and OBL activity was discovered, all muscles supporting the expiration phase. During phonation, the upper TR contributes in the compression of upper TX, thus serving as an accessory muscle of expiration. Group results from both opera singers and student singers showed that EMG activity was significantly lowered after BF. The lowered TR activity resulted in an expanded upper TX circumference and less TX respiratory movement after BF.     

Jaw Opening in Novice and Experienced Classically Trained Singers

This study examined the amount of jaw opening used by two groups of singers, those with less than 4 years of training (novice) and those with more than 8 years of training (experienced) in the Western tradition of opera and art song. Movement of the jaw in the superior-inferior plane was measured with the use of a lightweight head-mounted cephalostat with a strain gauge. The subjects spoke and then sung a carrier phrase "I say b(v)p," where (v) was each of three vowels, [a], [i], and [u]. The phrase was first spoken with a natural inflection and then sung on a repeated pitch at three notes from the low, medium, and high singing voice range. There was no statistically significant difference in jaw opening between the two groups of singers. Vowel was significant for jaw opening in both groups, with [a] being produced with more jaw opening than [i] or [u]. The voicing condition was also significant for jaw opening with greater jaw opening being used as pitch increased. In general the amount of jaw opening was smallest for the low singing voice condition and greatest for the high singing voice condition. The jaw opening most typically was less in the low voice condition than in the speech condition and then increased for both the medium and high voice tasks. All but two singers used more jaw opening on the [a] vowel than the other two vowels at all voicing conditions.     

Imprecise singing is widespread

There has been a recent surge of research on the topic of poor-pitch singing. However, this research has not addressed an important distinction in measurement: that between accuracy and precision. With respect to singing, accuracy refers to the average difference between sung and target pitches. Precision, by contrast, refers to the consistency of repeated attempts to produce a pitch. A group of 45 non-musician participants was asked to vocally imitate unfamiliar 5-note melodies, as well as to sing a series of familiar melodies from memory (e.g., Happy Birthday). The results showed that singers were more accurate than they were precise, and that a majority of participants could justifiably be categorized as imprecise singers. Accuracy and precision measures were correlated with one another, and conditional-probability analyses suggested that accuracy predicted precision more so than the converse. Finally, performance differences across groups of singers were greater for the imitation of unfamiliar tone sequences than for the recall of familiar melodies.     

Prevalence of and Risk Factors for Self-Reported Voice Problems Among Carnatic Singers

BackgroundUnlike Western opera singing, Carnatic singing requires powerful low pitched, loud voice. Singing in the right Shruti or pitch and appropriate breathing is given the main emphasis in this style of music. The present study was conducted to explore the prevalence of and possible risk factors for the self-reported voice problem (VP) in Carnatic singers.MethodThis cross-sectional survey was conducted by distributing the self-reporting questionnaires to 190 Carnatic singers in and around the Mysuru and Bengaluru districts of Karnataka state, India, from December 2016 to April 2017.ResultsThe Carnatic singers were found to have high career (35%) and point (23%) prevalence rates of VP. Clenching of teeth, frequent cold, difficulty in hearing, stress related to the profession, and regular intake of medications for different health-related problems were some of the risk factors found to have a significant association with high prevalence of self-reported VPs. Around 22% of the Carnatic singers missed at least 2–5 singing performances due to VP during their career.ConclusionsOverall, the results of this study reveal a high prevalence rate of self-reported VP in Carnatic singers, and they also suggest that the VPs are associated with different risk factors like any other form of singers. Further studies are needed to understand the effect of VP and to prevent it in this group of professional voice users.     

Acoustic comparison of voice use in solo and choir singing

An experiment was carried out in which eight bass/baritone singers were recorded while singing in both choral and solo modes. Together with their own voice, they heard the sound of the rest of the choir and a piano accompaniment, respectively. The recordings were analyzed in several ways, including computation of long-time-average spectra for each passage, analysis of the sound levels in the frequency ranges corresponding to the fundamental and the "singer's formant," and a comparison of the sung levels with the levels heard by the singers. Matching pairs of vowels in the two modes were inverse filtered to determine the voice source spectra and formant frequencies for comparison. Differences in both phonation and articulation between the two modes were observed. Subjects generally sang with more power in the singer's formant region in the solo mode and with more power in the fundamental region in the choral mode. Most singers used a reduced frequency distance between the third and fifth formants for increasing the power in the singer's formant range, while the difference in the fundamental was mostly a voice source effect. In a choral singing mode, subjects usually adjusted their voice levels to the levels they heard from the other singers, whereas in a solo singing mode the level sung depended much less on the level of an accompaniment.     

Effects of Vocal Training and Phonatory Task on Voice Onset Time

OBJECTIVES/HYPOTHESIS: The purpose of this study was to examine the temporal-acoustic differences between trained singers and nonsingers during speech and singing tasks. METHODS: Thirty male participants were separated into two groups of 15 according to level of vocal training (ie, trained or untrained). The participants spoke and sang carrier phrases containing English voiced and voiceless bilabial stops, and voice onset time (VOT) was measured for the stop consonant productions. RESULTS: Mixed analyses of variance revealed a significant main effect between speech and singing for /p/ and /b/, with VOT durations longer during speech than singing for /p/, and the opposite true for /b/. Furthermore, a significant phonatory task by vocal training interaction was observed for /p/ productions. CONCLUSIONS: The results indicated that the type of phonatory task influences VOT and that these influences are most obvious in trained singers secondary to the articulatory and phonatory adjustments learned during vocal training.     

Pitch Matching Accuracy of Trained Singers, Untrained Subjects with Talented Singing Voices, and Untrained Subjects with Nontalented Singing Voices in Conditions of Varying Feedback

At a physiological level, the act of singing involves control and coordination of several systems involved in the production of sound, including respiration, phonation, resonance, and afferent systems used to monitor production. The ability to produce a melodious singing voice (eg, in tune with accurate pitch) is dependent on control over these motor and sensory systems. To test this position, trained singers and untrained subjects with and without expressed singing talent were asked to match pitches of target pure tones. The ability to match pitch reflected the ability to accurately integrate sensory perception with motor planning and execution. Pitch-matching accuracy was measured at the onset of phonation (prephonatory set) before external feedback could be utilized to adjust the voiced source, during phonation when external auditory feedback could be utilized, and during phonation when external auditory feedback was masked. Results revealed trained singers and untrained subjects with singing talent were no different in their pitch-matching abilities when measured before or after external feedback could be utilized. The untrained subjects with singing talent were also significantly more accurate than the trained singers when external auditory feedback was masked. Both groups were significantly more accurate than the untrained subjects without singing talent.