Preliminary Findings of Vocal Fold Vibratory Characteristics of Singers Analyzed by Laryngeal High-Speed Videoendoscopy

OBJECTIVES

This study investigates the vocal fold vibratory dynamics of singers, which are postulated to differ from those of normal speakers due to the singers' regular vocal training. The measurement of vocal fold vibration involved the utilization of laryngeal high-speed videoendoscopy (LHSV) and subsequent LHSV-based analysis. The focus of the present study is to characterize and compare the LHSV-based measures derived from the glottal area waveform (GAW), namely fundamental frequency (F0GAW), glottal perturbation (jitterGAW and shimmerGAW), open quotient (OQGAW), and Nyquist plots, between singers and normal speakers across genders.

METHODS

Participants comprised 13 singers from a local cultural and heritage academy and 56 normal speakers from a local university, all were evaluated to have normal voices. Each participant underwent LHSV procedures to capture images of vocal fold vibration, which were subsequently analyzed to generate the LHSV-based measures.

RESULTS

Male singers exhibited lower F0GAW, jitterGAW, shimmerGAW, and OQGAW than female singers. When compared to normal speakers, male singers demonstrated higher F0GAW, and lower jitterGAW and shimmerGAW. No difference in OQGAW was found between male singers and normal speakers. Female singers exhibited lower jitterGAW compared to normal speakers, but no differences were observed in shimmerGAW and OQGAW. The results of Nyquist plots indicated no gender-related associations between types of rim width and among singers. However, for rim pattern, male singers were associated with a higher percentage of clustered rim, suggesting more regular vocal fold vibration, compared to female singers and normal male speakers.

CONCLUSIONS

Singers, particularly male singers, demonstrate distinct and potentially superior vocal fold vibrations compared to normal speakers, likely attributed to their regular vocal training, resulting in refined vocal fold configurations even during speaking. Despite the limited sample of singers, the study offers valuable insights into the vocal fold vibratory behaviors in singers analyzed using LHSV.

Towards a Vocal and Acoustic Description of Kapa Haka

OBJECTIVE

The purpose of this study is to analyze the voice used in kapa haka, a contemporary indigenous vocal performance from New Zealand, which includes the well-known haka. This is the first study of its kind and is a preliminary investigation into the vocal and acoustic description of kapa haka. A significant goal of this study is to contribute ideas and potential definitions of vocal qualities to the community of kapa haka trainers that were specific to the genre. This strengths-based project raises up these vocal practices as legitimate and authentic colors within a vocal tradition that has seen generational learning disrupted by colonial interventions and is now flourishing within the community.

METHODS

Eight kapa haka performers (three females, five males) were involved in the study, they were all experienced performers; furthermore, two had formal classical voice training. They were individually recorded speaking and performing three different genres of kapa haka (mōteatea, waiata, and haka); all recordings were in te reo Māori (the Māori language). In addition, electroglottograph (EGG) signals were collected. An auditory-perceptual evaluation of the kapa haka voice was completed by three singer-researcher-pedagogues familiar with Western and non-western genres of singing. They all have experience appropriately collecting and analyzing data from indigenous communities, and they all understand the sociopolitical context of the vocal genre within the local colonial history. A specific evaluation instrument was created, and the results were validated. The acoustic and time-aligned EGG data was annotated at the phoneme level, and the signal analysis was performed in MATLAB. Averaged EGG pulses from /a/ segments were investigated, along with long-term average spectrums of the performances obtained from both the audio signal and the EGG signals.

RESULTS

The perceptual analysis suggests the biggest difference in vocal styles was between the haka and the other two genres (and speech). The acoustic and EGG results support these findings.

CONCLUSIONS

Common characteristics, perceptually and acoustically, were identified in the kapa haka performance styles across the eight performers.

Frequency Range Measures in Carnatic Singers

BACKGROUND

Frequency range measures in singers reflect their physiological capacity, vocal flexibility, training effects, strengths, and limitations in singing. Since this information is vital for pedagogic and clinical purposes, this study aimed to measure the frequency range in Carnatic singers while singing different aspects of the vocal music.

METHOD

Practice task (gliding from lowest to highest note) and performance task (singing a song with vocal ornaments) were recorded from 55 trained Carnatic singers (40 females and 15 males). The auditorily verified portions of various vocal ornaments in Carnatic singing (such as aalapanai, pallavi, anupallavi, charanam, and niraval) were coded as separate tokens. A total of 385 tokens were analyzed using PRAAT software for estimating frequency range in semitones during practice task (SFR_prac) and performance task (SFR_perf). Descriptive, ANOVA, Tukey HSD, independent t, and Mann-Whitney U were used for statistical analysis.

RESULTS

SFR_prac was higher than SFR_perf in Carnatic singers. During practice, singers explored their physiological range to improve their vocal ability. However, during performance they tend to maintain a comfortable singing range to have a flawless rendition. Aalapanai (most creative portion) had the highest frequency range (females: 22.96 ST, males: 24.57 ST) than other types of vocal ornaments in performance signing. Practice frequency range (SFR_prac) and performance frequency range (SFR_perf) were not statistically different across male and female singers.

CONCLUSION

This study described the frequency range measures in various aspects and nuances of Carnatic singing. Its clinical and pedagogic importance are discussed.

Acoustic Analysis of Voice in Singers: A Systematic Review

PURPOSE

Singers are vocal athletes having specific demands from their voice and require special consideration during voice evaluation. Presently, there is a lack of standards for acoustic evaluation in them. The aim of the present study was to systematically review the available literature on the acoustic analysis of voice in singers.

METHOD

A systematic review of studies on acoustic analysis of voice in singers (PubMed/MEDLINE, CINAHL, Scopus, ProQuest, Cochrane, Ovid, Science Direct, and Shodhganga) was carried out. Key words based on PIO (population-investigation-outcome) were used to develop search strings. Titles and abstracts were screened independently, and appropriate studies were read in full for data extraction.

RESULTS

Of the 895 studies, 26 studies met the inclusion criteria. Great variability was noted in the instruments and task used. Different acoustic measures were employed, such as fundamental frequency, perturbation, cepstral, spectral, dysphonia severity index, singing power ratio, and so forth.

CONCLUSION

Overall, a great heterogeneity was noted regarding population, tasks, instruments, and parameters. There is a lack of standardized criteria for the evaluation of singing voice. In order to implement acoustic analysis as a part of comprehensive voice evaluation exclusively for singers, there is a certain need for methodical sound studies.