Objective Measures of Two Musical Interpretations of an Excerpt from Berlioz's "La Mort D'ophélie"

OBJECTIVE MEASURES OF TWO MUSICAL INTERPRETATIONS OF AN EXCERPT FROM BERLIOZ'S "LA MORT D'OPHÉLIE"

Hiu Yan (Crystal) Lau

A Thesis

Submitted to the Graduate College of Bowling Green State University in partial fulfilment of the requirements for the degree of

MASTER OF SCIENCE

May 2020

Committee:

Ronald C. Scherer, Advisor

Jane Schoonmaker Rodgers

Emily Pence Brown

Hiu Yan (Crystal) Lau

ABSTRACT

Ronald C. Scherer, Advisor

Objective: Art song is a unique genre in the realm of European classical music, which embraces the combined beauty of vocal melody, instrumental accompaniment, and text. In a performance context, the same composition can be performed with a variety of emotional interpretations. The purpose of this study was to determine sound production differences relative to two emotional interpretations in performing an excerpt from a classical art song.

Methods/Design: The first author, a soprano with a master’s degree in vocal performance, recorded an excerpt from “La Mort d’Ophélie” composed by Hector Berlioz (1803-69). The excerpt was sung in two contrasting musical interpretations: an “empathetic legato” approach, and a “sarcastic” approach with emphatic attacks. Microphone, airflow (Glottal Enterprises

MSIF-2), and electroglottography (EGG; Kay Model 6103) signals were digitized. These recordings were analyzed for acoustic, airflow, and glottographic measures. The vowels in the musical excerpt were analyzed in terms of intensity, long term average spectra (LTAS), fundamental frequency vibrato rate and extent, vowel onset, intensity comparison of harmonic frequencies, and glottal measures based on electroglottograph waveforms.

Results & Conclusions: Data analyses revealed that stressed vowels, when performed with the emphatic approach compared to the legato approach, had faster vowel onset, increased glottal adduction (relative to the EGGW25 measure), increased intensity of harmonics in the 1500 to

3000 Hz range, inferred increase in subglottal pressure, increased airflow for the /f/ consonant, and greater aspiration airflow for the plosives /t/ and /p/. The vibrato extent for both fo and airflow were both greater for the emphatic approach. Findings also revealed larger amplitude iv values of the EGG waveform, but this finding was not statistically significant. Long-term average spectrum (LTAS) analyses of the entire production displayed minor increases across all formant frequencies for the emphatic approach.

While this is a single-case objective study, it emphasizes the reality and informative nature of physiological, aerodynamic, and acoustic production differences in the pedagogical and interpretive aspects of art song performance. Vocal performers, teachers, and other music educators may benefit from applying findings like those of this study to developing performance strategies while maintaining healthy vocal production.

To my paternal Grandma,

who taught me how to play Für Elise for the first time,

and showed me what a smile can conquer.

To my maternal Grandma, who entered the Heaven after her battle against COVID-19 in April 2020,

and demonstrated why language barrier did not stop her from

spreading love and kindness. vi

ACKNOWLEDGMENTS

The completion process of this study, as well as this graduate degree, was nothing but full of adventures and exciting discoveries. I owe my deepest gratitude to my thesis supervisor, Dr.

Ronald C. Scherer. I first met Dr. Scherer as a client at BGSU Speech and Hearing Clinic, then as a student in his Voice Science and Voice Disorders classes. Having the opportunity to become the first graduate student in the voice science specialization has sparked my curiosity in voice science and vocal pedagogy. It was truly a blessing and honor to work with such a knowledgeable and wonderful thesis supervisor, fellow vocal music enthusiast, as well as a supporter of dad jokes and chocolate.

I am extending my gratitude to Dr. Johan Sundberg, Ph.D., for sharing his expertise in inverse filtering, which is an integral help for this research study. Tack ska du ha.

I would like to make a special thank you to my faculty committee members, Dr. Jane

Schoonmaker Rodgers, D.M.A., and Dr. Emily Pence Brown, Ph.D. They agreed to join my committee without any hesitation, and offered abundant emotional support during this process. I could not thank them enough for jumping into this bandwagon – and thankfully, what a ride.

Singing led me to embark on my academic journey in the United States. There are too many people I need to thank. First and foremost, I would like to thank both of my voice professors at the College of Musical Arts, Professor Sujin Lee, M.M., and Professor Myra

Merritt-Grant, M.M. Not only have they helped me to become the singer I am now, but also were the perfect examples of professionalism and artistry. Second, I would like to thank the Voice

Department for giving me another opportunity to pursue singing. In addition, I want to thank Dr.

Eftychia Papanikolaou, Ph.D., Dr. Elizabeth Menard, Ph.D., Dr. Mark Munson, D.M.A., and

Professor Kevin Bylsma, M.M., for all the knowledge and resources they selflessly shared. vii

Being more than eight thousand miles away from home, I owe my gratitude to my parents, Stephen and Angela. Thank you for introducing me to this world, and helping me to become the strong woman I am today. Day after day, they have been supporting my ambitions and endeavors, and willing to learn about my work. Also, thank you for still calling me Piggie

Bun, no matter how old I am.

Most importantly, I am grateful to know that I am not alone as a graduate student in

Interdisciplinary Studies. In fact, they are the angels whom I do not deserve to have. Without them, I truly would not have known how to survive these past two years as an international student. First and foremost, I would like to thank all the staff at BGSU International Programs and Partnerships, especially Dr. Marcia Salazar-Valentine, Ph.D., Maite Hall, Sara Smith, Betsy

Herman, and Grant Mierzejewski. Thank you for all your emotional support and opportunities, in order for me to make Bowling Green my second home. Secondly, I would like to thank all my colleagues and friends: Ruby Wing Tung Chiu, Ph.D., Rachael Cammarn, M.M., Seth Johnson,

Caroline “Carrie” Kouma, M.M., Carolyn Fagerholm, M.M., Mickey Miller, M.M., Julia Gries,

Laura Burger, Jhané Purdue, Brianna England, Bailey Maxfield, Carolyn Anderson, Jamison

Piatka, Debora Lazarean, Adrienne Ansel, Ayumi Sasaki, and Isabel Souza. You all have been my support system, no matter how long we have known each other – thank you for being the safety net I can always fall back on. Also, I would like to thank my friends at the First United

Methodist Church and the Older Adult program at BGSU Student Recreation Center. Thank you for being my surrogate families away from home. Last and most importantly, I would like to thank TJ Neuhaus – my best friend, boyfriend, voice lab buddy, fellow cold brew coffee lover, and confidant. Thank you for all the coffee, ramen, and dad jokes when I needed them the most – and also, “WiFi but po.” viii

PREFACE The thesis project serves as an extension of a research training project completed in 2018 under the supervision of Dr. Ronald C. Scherer, Ph.D., as a graduation requirement for the

Master of Music in Vocal Performance: Specialization in Voice Science and Pedagogy. The basic goal, to be described in detail below, is to extend the analyses more completely and address additional research questions.

TABLE OF CONTENTS

Page

INTRODUCTION………………………………………………………………………….…. 1

LITERATURE REVIEW……………………………………………………………………… 3

RESEARCH PURPOSE AND HYPOTHESIS……………………………………………….. 6

METHODS…………………………………………………………………………….……… 7

RESULTS …………………………………………………………………………………… 10

Intensity ………………………………………………………………………………. 10

Vowel Onset …………………………………………………………………………. 12

Harmonic Analysis …………………………………..………………………………. 13

Formant Analysis in Long-Term Average Spectrum (LTAS) ………………………. 18

Vibrato Extents ………………………………………………………………………. 20

Fundamental Frequency (fo) Vibrato

Extent ………………………………………………………………………… 22

Airflow Vibrato Extent ……………………………………………………… 22

Comparison between fo Vibrato and Airflow Vibrato Extents ………………. 23

Electroglottography (EGG) ………………………………………………………….. 25

EGGW25 …………………………………………………………………….. 25

EGG Signal Amplitude …………………………………………………….... 27

Inverse Filter ………………………………………………………………………… 30

Closed and Opening Quotients ……………………………………………… 31

Skewing Quotient …………………………………………………………… 33

French Consonant Production ………………………………………………………... 35

Voice Onset Time and Consonant Duration ………………………………… 35

Airflow ……………………………………………………………………….. 37

DISCUSSION………………………………………………………………………………… 40

Acoustic Measures …………………………………………………………………… 40

Glottographic Measures ……………………………………………………………… 41

Aerodynamic Measures ……………………………………………………………… 41

Limitations …………………………………………………………………………… 42

Application of Findings ……………………………………………………………… 42

CONCLUSION……………………………………………………………………………….. 44

REFERENCES………………………………………………………………………………... 45 xi

LIST OF FIGURES

Figure Page

1 Selected Excerpt from Hector Berlioz’s Art Song “La mort d’Ophélie” ...... 7

2 Lyrics, Corresponding Translation, and Transcription of Selected Excerpt from Hector

Berlioz’s “La mort d’Ophélie”...... 8

3 Microphone Signal Contours of Selected Vowels ...... 13

4 Harmonic Comparison between Legato and Emphatic Approaches ...... 14

5 LTAS Comparison between Legato and Emphatic Approaches across Excerpt

Productions ...... 19

6 Intensity Comparison between Legato and Emphatic Approaches from LTAS

Analysis ...... 19

7 Fundamental Frequency Comparison between Legato and Emphatic Approaches from

LTAS analysis ...... 20

8 Airflow and Fundamental Frequency Vibrato Waveforms in Legato Approach ...... 21

9 Airflow and Fundamental Frequency Vibrato Waveforms in Emphatic Approach .. 22

10 Comparison of Fundamental Frequency Vibrato Extents between Legato and Emphatic

Approaches ……………………………………………………………………. 24

11 Comparison of Airflow Vibrato Extents between Legato and Emphatic

Approaches ...... 25

12 Comparison of EGGW25 Values across Selected Vowels between Legato and

Emphatic Approaches ……………………………………………………………. 27

13 Comparison of EGG Waveform Amplitude between Legato and Emphatic

Approaches of Consecutive Phonatory Cycles during Production of “trop” /ɔ/ ……. 28 xii

14 Comparison of Mean EGG Waveform Amplitude Values across Selected Vowels

between Legato and Emphatic approaches …………………………………………. 30

15 Comparison of Closed Quotients (CQ) in Selected Vowels between Legato and

Emphatic Approaches ………………………………………………………………. 32

16 Comparison of Opening Quotients (OQ) in Selected Vowels between Legato and

Emphatic Approaches ………………………………………………………………. 33

17 Comparison of Skewing Quotients (SQ) in Selected Vowels between Legato and

Emphatic Approaches ………………………………………………………………. 34

18 Selected Consonant Phonemes Selected in Praat Software ………………………… 36

19 Comparison of Maximal Airflow Values in Selected Consonants

between Legato and Emphatic Approaches ………………………………………… 38

20 Comparison of Maximal Smoothed Airflow Values in Selected Consonants

between Legato and Emphatic Approaches ………………………………………… 38

21 Airflow Signal Contours in Selected Consonant Phonemes ………………………… 39

xiii

LIST OF TABLES

Table Page

1 Overall Intensity Analysis of Legato and Emphatic Approaches ...... 10

2 Intensity Analysis of all Vowels in Legato and Emphatic Approaches ...... 11

3 Intensity Differences between Legato and Emphatic Approaches in the Fourth and

Fifth Harmonic Frequency Values ...... 17

4 Intensity Differences between Legato and Emphatic Approaches in the First Eight

Formant Frequency Values ...... 18

5 Fundamental Frequency Vibrato Extent Differences between Legato and Emphatic

Approaches in Selected Vowels ……………………………………………………. 23

6 Airflow Vibrato Extent Differences between Legato and Emphatic Approaches in

Selected Vowels ...... 24

7 EGGW25 Values between Legato and Emphatic Approaches in Selected Vowels. 26

8 EGG Waveform Values between Legato and Emphatic approaches in Selected

Vowels …………………………………………………………………… 29

9 Closed Quotients (CQ) and Opening Quotients (OQ) of Selected vowels……… 32

10 Skewing Quotients (SQ) of Selected Vowels ...... 34

11 Maximal Airflow and Maximal Smoothed Airflow Values in Selected Consonant

Phonemes ………………………………………………………………………….. 37 1

INTRODUCTION

Art song is a unique genre in the realm of Western art music, which embraces the combined beauty of vocal melody, instrumental accompaniment, and text. The subject of this research project is the Primary Investigator (PI) and first author of this study. She recorded an excerpt from a composition by French composer Hector Berlioz (1803-69). The excerpt was sung in two contrasting musical interpretations: the traditional legato approach, and an emphatic approach (i.e., each word was articulated with emphasis.1). Analyses to obtain acoustic, aerodynamic, and electroglottographic (EGG) measures were conducted. These involved intensity differences of selected words, fundamental frequency and airflow extents in vibrato in selected vowels, vowel onset observed from audio signal contours, harmonic intensities in selected vowels, vocal fold adduction (EGGW25), glottal flow analyses from inverse filtering, voice onset time of production in French stops /p, t/, duration of production of French consonants

/f, r/, as well as maximal airflow during production of said consonants. The research question was: How do these quantifiable measures differ between the two interpretations?

Those recordings and partial analyses were made during a research training opportunity associated with the voice science and pedagogy specialization program completed by the PI in

2018. This thesis study extends the analyses of those recordings and provides additional information on the performance, pedagogical, and clinical applications. Specifically, the additional measures included intensity differences across all vowels, formant frequencies in long-term average spectra (LTAS) across all vowels, amplitudes of EGG waveforms, inferring degree of vocal fold contact during singing2, airflow vibrato extent across vowels during

1 “Emphatic.” Merrium-Webster Dictionary, accessed 12/15/2019, https://www.merriam-webster.com/dictionary/emphatic. 2 Hapala, Garcia, Švec, Scherer, & Herbst (2015). Relationship between the electroglottographic signal and vocal fold contact area. Journal of Voice, 30(2), 161-171. DOI: 10.1016/j.voice.2015.03.018. 2 phonation, subglottal pressure variation inferred from airflow vibrato extent, rates of fundamental frequency vibrato, as well as the comparison between airflow vibrato and fundamental frequency vibrato waveforms.

LITERATURE REVIEW

Art song can be defined as a short form of Western "classical" chamber music which originated in Europe in the early 19th century. Art songs are written for voice and piano, with texts usually taken from poetry or literature.3

Scherer, Sundberg, Fantini, Trznadel, and Eyben (2017) indicated that quantifying musical interpretations is difficult relative to isolating the emotional aspect of singing from other quantifiable measures, such as acoustics and articulation.4 With the assistance of technological tools, more recent vocal expression studies have presented information on intensity (perceived loudness), fundamental frequency (pitch), and spectral qualities (voice quality).5, 6 While the acoustic data provide quantifiable data, current literature has not discussed airflow events.

Sundberg et al. (2004) highlighted the different levels of glottal adduction in various musical singing styles.7 The subjects were asked to sing in various modes of phonation, styles, and loudness levels. The raw recordings were rated by a panel of listeners with extensive singing backgrounds.8 Classical singing style singing had the highest mean Normalized Amplitude

Quotient (NAQ) with the least mean subglottal pressure. Its sound quality was perceived as between “breathy” and “flow” (“flow” quality is determined as between “breathy” and

“neutral”).9 In terms of pressedness, classical singing had the lowest mean rating among the

3 Chew, G., Mathiesen, T. J., Payne, T. B., & Fallows, D. (2001). “Song,” Oxford Music Online, accessed 12/24/2019, https://doi.org/10.1093/gmo/9781561592630.article.50647. 4 Scherer, K., Sundberg, J., Fantini, B., Trznadel, S., & Eyben, F. (2017). The expression of emotional in the singing voice: Acoustic patterns in vocal performance. The Journal of the Acoustical Society of America, 142, 1805-15. DOI: 10.1121/1.5002886. 1806. 5 Bachorowski, J. A., & Owren, M. J. (2003). Sounds of emotion: Production and perception of affect-related vocal acoustics. Annals of the New York Academy of Sciences, 1000(1), 244-265. DOI: 10.1193/annals.1280.012. 6 Scherer, K. R. (2003). Vocal communications of emotion: A review of research paradigms. Speech Communication, 40, 227-256. 7 Sundberg, J., Thalén, M., Alku, P., & Vilkman, E. (2004). Estimating perceived phonatory pressedness in singing from flow glottograms. Journal of Voice, 18(1), 56–62. 57. 8 Sundberg, et al. (2004). 58. 9 Sundberg, et al. (2004). 59, 61. 4 recorded styles, regardless of loudness. The mean pressedness rating of classical singing was also similar to that of the “flow” phonation.10

The definition of “flow” phonation can be illustrated by the glottal configurations.

Research conducted in the Czech Republic concluded that “flow” phonation can be recounted as having a “cartilaginous glottal chink”, adduction of the true vocal folds, and no medialization of the ventricular vocal folds.11 It shares the identical comparison with “breathy” and “neutral” phonation with the ones in the Sundberg et al. (2004) study. “Breathy” phonation is described as having a “cartilaginous glottal chink” and a “membranous glottal chink”, with no medialization of the ventricular vocal folds. “Neutral” phonation was observed as adduction of both the cartilaginous and membranous portions of the glottis, with no medialization of the ventricular vocal folds.12 This illustrates how the adduction of the two glottal regions influences the perceived sound quality. Herbst et al.’s (2015) method of data collection is relevant to our research study, since only a single participant was involved as both the singer and the Principal

Investigator.13

Classical singing is a style that requires specific training, i.e., studying with a voice teacher. The control of subglottal pressure must be precise to control loudness and to avoid pitch errors. Singers rely less on adjustment of vocal fold adduction to alter loudness, while non- singers utilize it when they generate a louder voice.14 Interestingly, Sundberg (1990) pointed out that sopranos, like non-singers, do not rely on the “singer’s formant” as much as other classical voice types (or “fachs”), such as basses, baritones, tenors, and contraltos. One possible

10 Sundberg, et al. (2004). 59. 11 Herbst, C. T., Hess, M., Müller, F., Švec, J. G., & Sundberg, J. (2015). Glottal Adduction and Subglottal Pressure in Singing. Journal of Voice, 29(4), 391–402. 399. 12 Ibis. 13 Herbst et al. (2015). 392. 14 Sundberg (1990). 110-1. 5 explanation for such a claim would be that sopranos utilize more “head resonance”. As they sing with higher pitches using back vowels, the mouth is opened more to increase the first formant so that the fundamental frequency does not rise above the first formant.

RESEARCH PURPOSE AND HYPOTHESIS

The purpose of this research project was to explore two different specific interpretations of classical art songs: (1) a traditional legato approach with a “sympathetic” interpretation, and

(2) using emphatic vocal attacks with a “sarcastic” interpretation.

A note about the interpretations: The first approach was to sing in a legato manner

(connected, linear, smooth), with a sympathetic interpretation. It is important to point out that the legato approach may also have other affect interpretations such as calm, peaceful, regretful, mournful, sad, etc. Likewise, the second approach was to sing in an emphatic manner (marcato, declamatory, accented) with a sarcastic interpretation. Again, it can be pointed out that other affect interpretations could be excited, intense, aggressive, angry, etc.

The independent variable was the performance context, i.e., the use of the legato or emphatic treatment, and the emotions involved. The outcomes, i.e., the dependent variables, are the analyses of selected vowels and consonants, which will be elaborated in acoustic, aerodynamic, and physiological measures. A null hypothesis will be proposed, such that the two musical interpretations would result in identical outcome measures.

METHODS

At the time of the voice recording, the subject was a 28-year-old semi-professional singer with 7 years of classical voice training. She reported a history of laryngopharyngeal reflux (LPR) for 5 years, and one year of voice therapy. She reported to be physically healthy and vocally healthy at the time of recording. The subject sang as excerpt from the art song La mort d’Ophélie by Hector Berlioz (see Figures 1 and 2).

Figure 1

Selected Excerpt from Hector Berlioz’s Art Song “La mort d’Ophélie”

Figure 2

Lyrics, Corresponding Translation, and Transcription of Selected Excerpt from Hector Berlioz’s “La mort d’Ophélie”

The training study called for a microphone, an electroglottograph (EGG) (KAY Model

6103), an analog-to-digital converter (DATAQ DI-2108), and an aerodynamic recording system

(Glottal Enterprise MSIF-2). The microphone was positioned approximately 5 cm away from the subject’s mouth. EGG electrodes were placed on both sides of the laryngeal prominence.

The subject performed the excerpt in two distinct performance styles:

1. Full legato, smooth, sympathetic and melodic

2. No legato, sarcastic, with emphatic attacks on every note

The recording sequence was as the following:

1(a). Full legato, smooth, sympathetic and melodic (without the flow mask)

1(b). Full legato, smooth, sympathetic and melodic (with the flow mask)

2(a). No legato, sarcastic, with emphatic attacks on every note (without the flow mask)

2(b). No legato, sarcastic, with emphatic attacks on every note (with the flow mask)

In order to generate viewable data, the recordings were digitized using WinDaq software into .WDQ files. These signals were then transferred into the Matlab-based custom software

Sigplot along with a calibration file (in .txt format). The following formulae were used to calibrate the signals:

F = 838.29 × V

P = 4.9345 × V

3 where F is airflow in cm /s, P is air pressure in cm H2O, and V = voltage from the devices.

The spectra of each raw acoustic recording were determined by spectrograms and spectral slices using Praat software (www.fon.hum.uva.nl/praat). Additional airflow analyses were conducted using the Sopran (Tolvan Data, Stockholm) software. Sopran was used to obtain the open quotient and speed quotient for the glottal flow cycles in a number of the stressed vowels.

This analysis suggests laryngeal adduction levels, and is compared to analyses of the EGG signal, which also reveals adductory differences.

When the subject of the study is also the Principal Investigator, there is the chance for bias in carrying out the protocol as well as analyzing and interpreting the results of the study.

The potential bias of this study appears to be minimalized because, at the time of recording, the subject was just learning about voice science and the measurement of voice and speech characteristics. Furthermore, she produced the two excerpts relative to an emotional interpretation that can be considered separate from and an anticipation to the objective results.

RESULTS

Intensity

Using Praat software, overall intensity values were extracted separately from the microphone recordings without the mask on the face. Generally speaking, the overall intensity is higher in the emphatic approach, approximately by 2 dB (see Table 1).

Table 1

Overall Intensity Analysis of Legato and Emphatic Approaches Mean Max Min Range s.d Legato 60.77 81.53 17.07 64.46 14.99 Emphatic 62.71 83.66 18.69 64.97 14.60

Twenty-seven vowels from the text were extracted from the recordings using Praat software. Table 2 shows the mean, maximum, minimum, and standard deviation values in intensity of each vowel in the legato and emphatic approaches, respectively. The intensity ratio between the vowels produced in the two corresponding approaches was calculated by mean intensity in emphatic approach divided by the mean intensity in the legato approach. The analysis revealed that the vowels from “mais” /ɛ/, “trop” /ɔ/ and “pauvre” /ɔ/ had the highest ratio values (1.082, 1.129, 1.123; shaded in green), and the vowels in “Ophélie” /ɛ, i/ and

“tombe” /ɔ̃/ had the lowest ratio values (1.000, 0.998, 1.003; shaded in orange). These vowels are then categorized into two groups for additional comparison.

Table 2

Intensity Analysis of All Vowels in Legato and Emphatic Approaches Word/syllable Mean Intensity Ratio between legato and (Vowels) Legato (dB) Emphatic (dB) emphatic mean intensity Mais /ɛ/ 63.66 68.89 1.08 trop /ɔ/ 65.01 73.38 1.13 fai- /ɛ/ 68.83 69.89 1.02 -ble /ə/ 66.73 67.41 1.01 la /a/ 68.32 71.95 1.05 ra- /a/ 70.80 69.64 0.98 -meau /o/ 69.59 70.64 1.02 pli- /i/ 73.64 76.79 1.04 -e /ə/ 69.30 74.75 1.08 se /œ/ 66.76 71.03 1.06 bri- /i/ 69.21 73.27 1.06 -se /ə/ 66.42 68.04 1.02 et /e/ 61.35 65.73 1.07 la /a/ 68.50 72.32 1.06 pau- /ɔ/ 69.25 77.75 1.12 -vre-O- /ɔ/ 70.59 73.76 1.04 -phe- /ɛ/ 77.81 77.88 1.00 -li- /i/ 77.16 76.99 1.00 -e /ə/ 74.94 71.84 0.96 tom- /ɔ̃/ 74.70 74.94 1.00 -be /ə/ 64.76 66.02 1.02 sa- /a/ 66.51 70.02 1.05 -guir /i/ 61.39 64.27 1.05 lan- /ɑ̃/ 62.68 68.24 1.09 da-a /a/ 61.95 65.78 1.06 la /a/ 60.29 63.84 1.06 main /ɛ/̃ 60.33 62.97 1.04 Mean 67.80 70.67 1.04 Max 77.81 77.88 1.13 Min 60.29 62.97 0.96 Range 17.52 14.91 0.17

Vowel Onset To compare vowel onsets between the legato and emphatic productions, the overall contours of the productions were visually compared and accessed by calculating their corresponding steepness (slope).

Δy Intenesity difference Slope = = Δx Duration of vowel onset

In Figure 3 the selected vowel productions are highlighted in pink (except for “mais”), and their corresponding vowel onset slope values (the slopes of the blue and red lines) are placed underneath each selected vowel production.

The vowel onset of each production is indicated by the colored lines (legato production in blue, emphatic production in red). In comparison to the legato productions, the vowel onsets in the emphatic productions are found to be more abrupt and quicker, as shown by the greater steepness of the red lines.

Figure 3

Microphone Signal Contours of Selected Vowels Word Legato Emphatic (Vowel) mais /ɛ/

(Slope = 0.19) (Slope = 5.72) trop /ɔ/

(Slope = 0.61) (Slope = 3.95) pauvre /ɔ/

(Slope = 3.61) (Slope = 14.15) Ophelie /ɛ/

(Slope = 16.05) (Slope = 20.79) Ophelie /i/

(Slope = 5.10) (Slope = 10.95) tombe /ɔ̃/

(Slope = 8.11) (Slope = 6.37) Mean 5.61 10.30 (s.d.) (5.89) (6.37) Note. Figure 3 displays the microphone signals extracted from the Praat software. For visibility purposes, all selected word productions except “mais” are highlighted in pink. The vowel onsets are indicated with colored lines (blue for legato productions, red for emphatic productions). The steepness of each vowel onset was measured from the colored lines’ slopes.

Harmonic Analysis

For each vowel production, a spectral slice (spectrum) was extracted using the Praat software. The first eight harmonic frequency values, as well as their corresponding intensity 14 values, were collected. In Figure 4, intensity increased across all six vowels in the fourth and fifth harmonic frequency values (H4 and H5) during the emphatic approaches compared to the legato approach. All H4 and H5 frequencies were in the range of 1500-3000 Hz, which essentially corresponds to the third through fifth formant frequency regions. According to Table

3, there is no specific trend in the intensity differences for H4 and H5 except for the generally higher intensity values for the emphatic approach.

Figure 4

Harmonic Comparison between Legato and Emphatic Approaches Word Comparison between Legato and Emphatic approaches (Vowel) mais /ɛ/

trop /ɔ/

pauvre /ɔ/

Ophelie /ɛ/

Ophelie /i/

tombe /ɔ/̃

Note. Figure 4 displays the harmonic frequencies extracted from the Praat software. The intensity increases in H4 and H5 are indicated with green boxes.

Table 3

Intensity Differences between Legato and Emphatic Approaches in the Fourth and Fifth Harmonic Frequency Values Intensity Differences between legato and emphatic approaches (dB) Word (Vowel) Fourth harmonic (H4) Fifth harmonic (H5) mais 10.3 6.4 /ɛ/ trop 17.4 9.9 /ɔ/ pauvre -3.2 2.3 /ɔ/ Ophelie -6.4 9.0 /ɛ/ Ophelie 8.4 13.1 /i/ tombe 3.3 3.0 /ɔ̃/

Formant Analysis in Long-Term Average Spectrum (LTAS)

The long-term average spectrum (LTAS) analysis is an approach to measure formant frequencies in human speech across a period of time. The LTAS analyses or the entire excerpts are shown in Figure 5. Using the RTSect software, the microphone recordings without the mask on the face were analysed five times to extract and calculate average formant frequency values and their corresponding intensity values. The intensity differences between the legato and emphatic approaches were calculated by mean intensityEMPHATIC – mean intensityLEGATO, as displayed in Table 4. It should be noted that the values from the seventh and eighth formants are included but were difficult to accurately identify. The intensities of the formants for the emphatic approach were consistently greater than those for the legato approach. These intensity differences are also seen in Figure 6.

Table 4

Intensity Differences between Legato and Emphatic Approaches in the First Eight Formant Frequency Values Formant Intensity (dB) F1 F2 F3 F4 F5 F6 F7* F8* Legato 43.75 38.75 27.75 26.875 19.125 13.25 7.375 8.625 Emphatic 45.3 42.8 32.1 27.5 24.9 19.7 10 10.6 Difference 1.55 4.05 4.35 0.625 5.775 6.45 2.625 1.975

Figure 5

LTAS Comparison between Legato and Emphatic Approaches across Excerpt Productions

Note. The LTAS for both productions display in Figure 5. The LTAS for the legato production is indicated by blue lines, and the LTAS for the emphatic production is indicated by red lines.

Figure 6

Intensity Comparison between Legato and Emphatic Approaches from LTAS analysis

Figure 7

Fundamental Frequency Comparison between Legato and Emphatic Approaches from LTAS Analysis

While the intensity levels of the formants were greater for the emphatic approach, Figure

7 indicates that the formant frequencies were nearly equal. These results suggest that the subject tended to sing with the same vowel formants in the two interpretations relative to formant frequencies, but tended to sing the emphatic interpretation with greater overall intensity (across the spectra).

Vibrato Extents

For this study, vibrato extent is defined as the difference between the maximum and minimum frequency values of a vibrato cycle within a specific vowel production. Two types of vibrato were studied: fundamental frequency (fo) vibrato and airflow vibrato. The recordings with the mask on the face were used for the frequency and smoothed airflow traces shown in 21

Figures 8 and 9. The quasi-vertical alternating signals in each trace indicate the presence of vibrato (cyclic change of the values).

Figure 8

Airflow and Fundamental Frequency Vibrato Waveforms in Legato Approach

Figure 9 Airflow and Fundamental Frequency Vibrato Waveforms in Emphatic Approach

Fundamental Frequency (fo) Vibrato Extent

The range of fo vibrato extents in the six selected vowels of both approaches are shown in

Table 5 (see Figure 10). In four out of six selected vowels, the fo vibrato extents in the emphatic approach are approximately two to three times wider, i.e., ratio = 1.55-2.72. The vowel productions for “trop” /ɔ/ and “Ophélie” /ɛ/ are included although their sound productions were relatively shorter than the other vowels.

Airflow Vibrato Extent

The range of airflow vibrato extents in the six selected vowels of both approaches are shown in Table 6 (see Figure 11). In four out of six selected vowels, airflow vibrato extents in the emphatic approach are approximately one to three times wider, i.e., ratio = 0.95-2.55. Again, the vowel productions for “trop” /ɛ-ɔ / and “Ophélie” /ɛ/ are included despite their sound production being relatively shorter than the remaining vowels. For the means and standard 23 deviation, the zero vibratos were excluded. The emphatic airflow vibrato extents are significantly greater than for the legato airflow vibrato. In comparison to fo vibrato extent ratios, the airflow vibrato extent ratio values are slightly less.

Comparison between fo Vibrato and Airflow Vibrato Extents

A further regression analysis was used to discern any potential correlation between

2 airflow and fo vibrato extent ratios. The R value of approximately 0.57 rejects a significant correlation but suggests that a more extensive study may indicate an interesting relationship.

Table 5

Fundamental Frequency Vibrato Extents for the Legato and Emphatic Approaches in Selected Vowels Word (Vowel) 1(a) Legato (Hz) 2(a) Emphatic (Hz) Ratio – 1(a) vs 2(a) mais /ɛ/ 68.12 122.31 1.80 *trop /ɔ/ 16.33 70.52 4.32 pauvre /ɔ/ 30.60 83.13 2.72 *Ophélie /ɛ/ 2.93 33.01 11.25 Ophélie /i/ 67.78 131.79 1.94 tombe /ɔ̃/ 63.11 97.73 1.55 Mean 41.48 89.75** 3.93 (s.d.) (28.66) (36.12) (3.72) s.d. = Standard deviation * Shorter vowel prolongation ** Statistically different (t-test), p = 0.028 < 0.05)

Table 6

Airflow Vibrato Extents for the Legato and Emphatic Approaches in Selected Vowels Word (Vowel) 1(b) Legato (cm3/s) 2(b) Emphatic (cm3/s) Ratio – 1(b) vs 2(b) mais /ɛ/ 103.79 201.44 1.94 *trop /ɔ/ 42.66 289.78 6.79 pauvre /ɔ/ 0 (No vibrato)* 0 (No vibrato)* n/a *Ophélie /ɛ/ 65.70 403.04 6.13 Ophélie /i/ 144.44 216.38 1.50 tombe /ɔ̃/ 201.16 191.76 0.95 Mean 111.55** 260.48 3.46 (s.d.) (63.29) (88.51) (2.77) s.d. = Standard deviation * Shorter vowel prolongation ** Statistically different (t-test), p = 0.004 < 0.05

Figure 10

Comparison of Fundamental Frequency Vibrato Extents between Legato and Emphatic Approaches

Figure 11

Comparison of Airflow Vibrato Extents between Legato and Emphatic Approaches

Figures 10 and 11 compare the effects of legato and emphatic approaches on, respectively, fundamental frequency vibrato and airflow vibrato. The above comparisons suggest that both airflow and fo vibrato extents are wider in the emphatic approach.

Electroglottography (EGG)

The glottographic data were collected using electroglottography. The Sigplot program extracted the EGGW25 and the amplitude values of the EGG signals from the non-masked recordings of the two excerpts.

EGGW25

The laryngeal adduction activity during phonation is elaborated by EGGW25, i.e., the width of the EGG signal at 25% of the amplitude of a completed cycle divided by the cycle’s 26 period15. Table 7 consists of the EGGW25 values from the six selected vowels in both approaches. The EGGW25 values in the emphatic approach are statistically higher than those in the legato approach, as also indicated in Figure 12. According to Scherer, Vail, and Rockwell16, the EGGW25 value corresponds to glottal adduction at the vocal processes.17 This suggests a higher laryngeal adduction during the emphatic performance.

Table 7

EGGW25 Values between Legato and Emphatic Approaches in Selected Vowels Word (Vowel) 1(a) Legato 2(a) Emphatic Difference mais /ɛ/ 0.25 0.32 0.07 trop /ɔ/ 0.23 0.25 0.02 pauvre /ɔ/ 0.26 0.33 0.07 Ophélie /ɛ/ 0.27 0.30 0.03 Ophélie /i/ 0.24 0.28 0.04 tombe /ɔ̃/ 0.27 0.35 0.08 Mean 0.25 0.31** 0.05 (s.d.) (0.02) (0.04) (0.02) s.d. = Standard deviation ** Statistically different (t-test), p = 0.010 < 0.05

15 Scherer, R. C., Vail, V. J., & Rockwell, B. (1993). Examination of the laryngeal addiction measure EGGW. In Bell-Berti, F., & Lawrence, R. J. (1995), Producing Speech: Contemporary Issues: for Katherine Safford Harris (pp. 269-290). Woodbury, New York: American Institute of Physics. 16 Ibid. 17 Ibid. 27

Figure 12

Comparison of EGGW25 Values across Selected Vowels between Legato and Emphatic Approaches

EGG Signal Amplitude

For this study, the EGG signal amplitude is defined as the height between the baseline and the local maximum within a complete cycle of the EGG signal. Similar to the EGGW25, these data were extracted from the raw recordings using the Sigplot program. Figure 13 illustrates, as an example, the variation of EGG waveform amplitude values during a vowel production.

Figure 13

Comparison of EGG Waveform Amplitude between Legato and Emphatic Approaches of Consecutive Phonatory Cycles during Production of “trop” /ɔ/

Note. Figure 13 demonstrates how EGG waveform amplitude varies during /ɔ/ production.

Overall, the mean amplitude values across the six selected vowels, except /ɔ̃/ (marked with * in Table 8), were found to be higher in the emphatic approach than the legato performance

(see Table 8). Such difference in the amplitudes between the two approaches suggests that the vocal folds contacted with greater area of contact for the emphatic excerpt compared to the legato excerpt. However, the difference between the two groups (excluding the values for

“tombe”) were not statistically significantly different. In Figure 14, the nasal vowel /ɔ̃/ from

“tombe” is again noted with opposite trend when compared with non-nasal vowels.

Table 8

EGG Waveform Amplitude Values between Legato and Emphatic Approaches in Selected Vowels Word 1(a) Legato 2(a) Emphatic Difference (Vowel) Mean s.d. Mean s.d. Mean s.d. mais /ɛ/ 0.45 0.05 0.57 0.03 0.12 -0.01 trop /ɔ/ 0.30 0.01 0.40 0.02 0.11 0.01 pauvre /ɔ/ 0.46 0.07 0.68 0.05 0.22 -0.02 Ophélie /ɛ/ 0.61 0.01 0.65 0.02 0.04 0.01 Ophélie /i/ 0.42 0.02 0.51 0.04 0.09 0.03 tombe /ɔ̃/ 0.45 0.07 0.05* 0.02 -0.40* -0.05 Mean* 0.44 0.03 0.56 0.03 0.12 0.002 (s.d.) (0.11) (0.03) (0.11) (0.02) (0.06) (0.02) * Excluding “tombe” s.d. = Standard deviation ** Not statistically different (t-test), p = 0.145 > 0.05

Figure 14

Comparison of Mean EGG Waveform Amplitude Values across Selected Vowels between Legato and Emphatic Approaches

Inverse Filter

The term “inverse filtering” describes the process of obtaining the glottal airflow from the wideband airflow from the mouth or from the microphone acoustic pressure in front of the mouth.18 For this study, Sopran was used to remove the effects of the vocal tract resonances to thus obtain the glottal flow. The airflow signals were isolated from recordings with the flow

18 Gobl, C., & Mahshie, J. (2013). Inverse filtering of nasalized vowels using synthesized speech. Journal of Voice, 27(2), 155-169. DOI: 10.1016/j.jvoice.2012.09.004 31 mask and then the formant filters were applied to these signals in Sopran. The initial estimated formant values were based on earlier studies of female speech. 19,20,21,22

Closed and Opening Quotients

The open quotient, OQ, is the ratio of time the glottis is open during the vibratory cycle, divided by the cycle period. The closed quotient, CQ, is one minus the OQ (CQ = 1 – OQ). The

CQ and OQ values of each selected vowel are shown in Table 9. All vowels except trop /ɔ/ and tombe /ɔ̃/ (marked with *) demonstrate increases in CQ and decreases in OQ during the emphatic approach. Figures 15 and 16 show comparisons in CQ and OQ values between the legato and emphatic approaches. All vowels except tombe /ɔ̃/ illustrate higher CQ and lower OQ values during the emphatic performance. The differences in OQ or CQ between the two excerpts were not statistically significant, and thus did not distinguish the two singing interpretations.

19 Peterson, G. E., & Barney, H. L. (1952). Control methods used in a study of vowels. The Journal of the Acoustical Society of America, 24, 175-184. DOI: 10.1121/1.1906875 20 Eguchi, S., & Hirsh, I. J. (1969). Development of speech sounds in children. In Acta oto-laryngologica (Vol. 257). Uppsala, Sweden: Almquist & Wiksells. 21 Hillenbrand, J., Getty, L. A., Clark, M. J., & Wheeler, K. (1995). Acoustic characteristics of American English vowels. The Journal of the Acoustical Society of America, 97, 3099-3111. DOI: 10.1121/1.411872 22 Lee, S., Potamianos, A., & Narayanan, S. (1999). Acoustic of children’s speech: Developmental changes of temporal and spectral parameters. The Journal of the Acoustical Society of America, 105, 1455-1468. DOI: 10.1121/1.426686 32

Table 9

Closed Quotients (CQ) and Opening Quotients (OQ) of Selected Vowels Word 1(b) Legato 2(b) Emphatic (Vowel) CQ OQ CQ OQ mais /ɛ/ 0.022 0.978 0.038 0.962 trop /ɔ/ 0.037* 0.963* 0.037* 0.963* pauvre /ɔ/ 0.034 0.966 0.042 0.958 Ophélie /ɛ/ 0.018 0.982 0.031 0.969 Ophélie /i/ 0.032 0.968 0.033 0.967 tombe /ɔ̃/ 0.038* 0.962* 0.030* 0.970* Mean 0.030 0.97 0.035** 0.96 (s.d.) (0.008) (0.01) (0.005) (0.004) s.d. = Standard deviation ** Not statistically different (t-test), p = 0.225 > 0.05

Figure 15

Comparison of Closed Quotients (CQ) in Selected Vowels between Legato and Emphatic Approaches

Figure 16

Comparison of Opening Quotients (OQ) in Selected Vowels between Legato and Emphatic Approaches

Skewing Quotient

The skewing quotient (SQ) for the glottal flow cycle is the time from baseline to the peak glottal flow divided by the time from the peak back down to the baseline. The SQ values of each selected vowel are shown in Table 10 and shown in Figure 17. The difference of the SQ between the two excerpts was not statistically different, and thus did not distinguish the two singing interpretations.

Table 10

Skewing Quotients (SQ) of Selected Vowels Word 1(b) Legato 2(b) Emphatic Difference (Vowel) mais /ɛ/ 0.816 0.565 -0.247 trop /ɔ/ 1.022 1.053 0.031 pauvre /ɔ/ 0.742 0.694 -0.048 Ophélie /ɛ/ 1.704 1.273 -0.431 Ophélie /i/ 1.018 1.155 0.136 tombe /ɔ̃/ 0.996 1.036 0.040 Mean 1.050 0.963** -0.087 (s.d.) (0.341) (0.275) (-0.067) ** Not statistically different (t-test), p = 0.637 > 0.05

Figure 17

Comparison of Skewing Quotients (SQ) in Selected Vowels between Legato and Emphatic Approaches

French Consonant Production

Voice Onset Time (VOT) and Consonant Duration

Voice onset time (VOT) for a stop consonant is defined as the length time between the burst at the moment of articulator separation to the time of phonatory onset.23 For VOT and other analyses of consonants, four consonantal phonemes were selected among the text, i.e., “faible”

/f/, “pauvre” /p/, “tombe” /t/, “trop” /tr/. Using the Praat software, the audio signals of recordings without the mask were imported. Figure 18 shows the selected portions from Praat, which are highlighted in pink. The duration of the /f/ productions were nearly identical, as was the production of /r/ in the /tr/ context. The VOT for the /p/ was also nearly identical between the two productions, as was the VOT for /t/. Thus, the timing aspects of the selected consonants were not differentiated relative to the two interpretations.

23 Klatt, D. (1975). Voice onset time, frication, and aspiration in word-initial consonant clusters. Journal of Speech and Hearing Research, 18(4), 686-706. DOI:10.1044/jshr.1804.686. 36

Figure 18

Selected Consonant Phonemes Selected in Praat Software Word 1(a) Legato 2(a) Emphatic (Consonant) (Duration) (Duration)

faible /f/

(0.1830 seconds) (0.1832 seconds)

pauvre /p/

(0.1473 seconds) (0.1421 seconds)

tombe /t/

(0.0144 seconds) (0.0130 seconds)

/t/ /t/

trop /tr/ /r/ /r/

(/t/ = 0.046 seconds; (/t/ = 0.037 seconds; /r/ = 0.037 seconds) /r/ = 0.026 seconds)

Note. Selected consonant productions are highlighted in pink. 37

Airflow

The same four consonantal phonemes, i.e., /f, p, t, tr/, were assessed using the Sigplot program. Since airflow signals were inspected, recordings with the flow mask were used. The maximum airflow and maximum smoothed airflow values are displayed in Table 11 and shown in Figures 17 and 18. In general, the maximum flows were greater in the emphatic productions compared to the legato productions, but there were too few data points to bring the differences to statistical significance. Greater airflows suggest greater values of subglottal pressure were used for the emphatic approach.

Table 11

Maximum Airflow and Maximum Smoothed Airflow Values in Selected Consonant Phonemes Legato Emphatic Word (Consonant) Maximum Maximum Maximum airflow smoothed Maximum airflow smoothed (cm3) airflow (cm3) (cm3) airflow(cm3) faible /f/ 439.8 403.6 388.6 335.1 pauvre /p/ 1132 1103 3714 3008 tombe /t/ 950.1 683.6 2697 2568 trop /t/ 728.9 528.2 5011 1892 Mean 812.7 679.6** 2952.65 1950.78*** (s.d.) (298.3) (304.6) (1954) (1171) s.d. = Standard deviation ** Borderline statistically different (t-test), p = 0.074 > 0.05 *** Borderline statistically different (t-test), p = 0.080 > 0.05

Figure 19

Comparison of Maximal Airflow Values in Selected Consonants between Legato and Emphatic Approaches

Figure 20

Comparison of Maximal Smoothed Airflow Values in Selected Consonants between Legato and Emphatic Approaches

The differences of airflow signal contours between the two approaches are notable, as confirmed by the Sigplot program. Figure 21 includes the corresponding airflow signal contours of the selected consonants in, respectively, the legato and emphatic approaches.

Figure 21

Airflow Signal Contours in Selected Consonant Phonemes

Note. The airflow signal contours were extracted using Sigplot. During the singing recording session, the amount of airflow varied between the two performance approaches. The y-axes on each production refers to the output airflow in cubic centimeters per second (cm3/s).

As shown, the airflow signal contours in the emphatic approach are less smooth than those in the legato approach. Such observation suggests that, because more subglottal pressure appears to have been present during the emphatic performance, greater airflow, therefore, contributed to the noise component for the selected consonants. 40

DISCUSSION The goal of this project was to explore objective differences between two specific interpretations when performing a selection from a classical art song. The first author sang an excerpt from “La mort d’Ophélie” composed by Hector Berlioz (1803-69) with an “empathetic legato” approach as well as with an “emphatic sarcastic” approach. To distinguish between the traditional legato and the emphatic approaches, the acoustic, aerodynamic, and physiological results will be discussed in this section.

Acoustic Measures

In the emphatic performance, the vowel onsets were found to be quicker and more abrupt.

This indicates a faster completion of glottal adduction at the beginning of the vowel production.

The spectral properties of each vowel can be observed in the harmonic and LTAS analyses, which highlighted a notable increase in the 1500-3000 Hz. Such frequency range, in human speech, is associated with the third through fifth formant regions, suggesting greater glottal adduction with greater subglottal pressure to alter the glottal flow giving rise to greater intensity in the frequencies of that region.24 This change most likely contributed to the increase in overall intensity of the emphatic over the legato productions.

Another aspect is the vibrato extents in fundamental frequency and airflow in the selected vowels. Both vibrato extents were found to be much wider in the emphatic approach. This suggests that more subglottal pressure, or more contraction from the cricothyroid muscles which are associated to variation in fundamental frequency (or “pitch”), were employed during the emphatic approach.

24 Scherer, 2017. 41

Glottographic Measures

The EGG analyses revealed higher EGGW25 and EGG waveform amplitude values for the emphatic compared to the legato versions. The EGGW25 values were statistically significantly different. Such difference can be hypothesized by an inferred increase in subglottal pressure and greater glottal adduction. Interestingly, all EGGW25 values, regardless of approaches, fall into the range of 0.2-0.4. Scherer, Vail, and Rockwell25 discovered such range as

“hypoadducted”, which means the vocal folds are slightly less close to each other during phonation, essentially in the “breathy” region during speech. This is consistent with the very low values of the closed quotient of the glottal flow signal. This singer used very little glottal adduction during her singing, although she used more adduction during the emphatic compared to the legato versions.

Aerodynamic Measures

There tended to be greater airflow for the emphatic approach compared to the legato approach relative to the production of the French consonants. At the end of data collection process, the participant indicated that the consonants in the emphatic performance were perceived to be closer to those in American English. This raises the question of how to enunciate the text appropriately, in order for the audience to understand the emotions, without losing the integrity of the language used for the musical excerpt.

The skewing quotient (SQ) values extracted from Sopran did not differentiate the two interpretations (there was no statistical difference). This observation suggests that the inertance of the vocal tract did not play a significant role during these singing productions. This may be

25 Scherer, Vail, & Rockwell. 1993. 272. 42 explained by the observation that the lower harmonic intensities were quite similar for both interpretations (where the skewing of the flow is highly dependent on those frequencies) and the fundamental frequencies were relatively high.

Limitations

For this study, four limitations should be mentioned. First, since this study only involves six selected words and four selected consonants from the text, future studies should include the entire text to give a more generalized differentiation between performance approaches. Second, future studies should investigate singers other than sopranos, as well as singers of all training levels. This would provide a deeper comparison between sexes and training, and enhance the understanding of how different groups of singers discern various performance approaches and musical interpretation. Third, relative to inverse filtering, the less complex shape of the glottal flow made it difficult to determine accurately the small closed phase of the cycle. Future studies could cross-check the results related to the glottal flow with multiple computerized programs, such as timing relationships revealed through EGG analyses and TF-32. Fourth, it is advisable to run subjects who are not co-investigators of the project, in order to minimize bias of the reactions and productions of the subjects as well as bias of the experimenters’ interpretation of the results.

Application of Findings

Relative to music performance, the findings provide insight into physiological perspectives as singers interpret the same piece of music differently. Similarly, the methods and findings can be applied to future studies, but in other classical genres, such as opera and oratorio works. This study also offers further questions in psychoacoustic perspectives, specifically on 43 how to balance between healthy sound productions and audience’s perception of sound quality and emotional interpretations.

The findings in this study can also provide additional reference relative to vocal pedagogy. Voice teachers and choral instructors might use the findings to consider more effective teaching strategies when working with singers on musical interpretation, without sacrificing the singers’ vocal health.

Such findings may also be beneficial in clinical contexts, especially combining healthy vocal production technique and variation in prosody, in order to interpret and communicate speech with different emotions. Future singing studies can be fostered by studying various musical genres, as well as the corresponding physiological and perceptual aspects of sound production.

CONCLUSION

In respond to the research question, “What are quantifiable measures that explain the difference between the legato and the emphatic approaches when performing the art song excerpt?”, the findings suggest that the emphatic approach is:

- Higher in harmonic intensity values in the range of 1500-3000 Hz, suggesting an increase

in the third through fifth formant frequency region due to an increased subglottal pressure

and glottal adduction;

- Wider vibrato extents in airflow vibrato and fundamental frequency vibrato, inferring a

potential increase in subglottal pressure;

- Greater laryngeal adduction (longer contact time between the vocal folds) as

demonstrated by higher values in EGGW25 values; and

- More airflow while performing emphatically in selected vowels and consonants,

suggesting an increase in subglottal pressure.

The findings above not only elaborate the differences between the legato and emphatic performance, but also provide additional insights into pedagogical, performance, and vocal rehabilitation perspectives. 45

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