The Science of the Singing Voice

1. The Science of the Singing Voice Overview of the course (HC16) Winter 2008 Pat Keating, Linguistics, UCLA

2. Books • Johann Sundberg, The Science of the Singing Voice. Northern Illinois University Press (1989) • Peter Ladefoged, Elements of Acoustic Phonetics. Second edition. University of Chicago Pres (1996) • Richard Miller, The Structure of Singing: System and Art in Vocal Technique. Wadsworth Publishing (2001) • Richard Miller, National schools of singing: English, French, German, and Italian techniques of singing revisited. Scarecrow Press (2002) • Garyth Nair, Voice – Tradition and Technology: A State-of-the-Art Studio. With CD. Singular (1999) • Ingo Titze, Principles of Voice Production (2nd printing 2000)

3. 1. Intro: Sundberg’s demo • Go to: The ugly voice poster • But we don’t do any synthesis in the course

4. F0 and pitch • Vibration, Hz • Tuning forks, vocal folds • Relations of Hz to musical notes and intervals (several websites with these) – see next slide • Tone generator in Audacity is another way to relate Hz to notes

5. Frequencies of piano white keys

6. Digital audio • SR, QR. compression • File formats – more complicated this year than in 2006! • We need song clips with a single voice (no instruments or other voices)

7. Review questions 1. Which tuning fork has the higher-sounding pitch, 392 Hz or 523 Hz? 2. What part of the body produces the fundamental frequency of the voice? 3. The frequency of the note G2 is 98 Hz. What is the frequency of G3? 4. Is a song on an audio CD or an mp3 player in .wav format?

8. Lab 1: audio clips • Ripping CD tracks to .wav (CDex, CLICC) • Ripping audio from commercial DVDs (DVDFab Decrypter to AnyAudioConverter) • Ripping audio from YouTube videos (Freecorder) • Saving .mp3 and various other audio formats as .wav (Audacity, CDex, AudioConverter) • Splitting and saving mono tracks from stereo (Audacity) • File clips kept on our ecampus Discussion Board

9. Examples • From Worst of AI DVD: • From AI on Youtube:

10. 2. From Sundberg • How do you experience your own voice? • Why does a recording of your voice sound different to you? • And, why do you sound better in the shower?

11. Pitch • Semi-tone = about 6% freq difference • “in tune”: how close to target is close enough (about 20 cents for average listener) • “in tune”: steadiness • Transitions between notes: swooping

12. Example: steadiness, swooping

13. Vibratos • Dimensions of vibrato • Rate, range, amplitude vibrato • Supposed good classical vibrato • 5.5 to 7 Hz rate, + .5 to 2 semitones range • What good a vibrato does, doesn’t do for the singer • Examples next slides

14. Example: D. Fischer-Dieskau

15. Example: Leontyne Price

16. Example: Joan Baez

17. Example: Kelly Clarkson

18. Lab 2 and Assn 1: vibratos • Pitchworks, wavesurfer • Measuring F0 from pitchtrack • Calculating vibrato properties

19. Tricks in pitchtracking • Hardest part: keeping track of F0 range and optimizing option settings • Tuning forks and thin voices: don’t use cepstral method, use autocorrelation • Problems tracking trills and other fast F0 changes: need to change step size and/or window length

20. 3. Larynx and phonation • Laryngeal anatomy: physical model, “Vocal Parts” CD, ASA and Painter videotapes, Youtube videos, (DVDs about source and about phonation) • Mechanisms of vocal fold vibration • F0 variation with airflow means pitch and loudness are correlated, which singers need to learn to decouple

21. 4. Spectrum • The voice source: F0 and overtones • Line spectrum of source • FFT of output in Audacity, wavesurfer • DVD “Human Speech”: a key point of this is that speed of closing of vocal folds determines strength of higher harmonics and thus the brightness of the voice

22. Partials, overtones? • Partials = harmonics • Overtones = partials above F0

23. Lab 3 and Assn 2: FFT • FFT, LTAS in Pitchworks or wavesurfer • FFT in Audacity: View-Plot spectrum (nice for comparing effect of window length; shows musical note of F0) • Pros, cons of Audacity vs Pworks/wavesurf • Comparing spectra of different voice qualities by strength of H1, number of harmonics, extent of high-freq energy

24. 5. Resonances • From Ladefoged on resonance • Basic source-filter idea • More of Source-Filter DVD, on filter • Vowel “covering”: lowering the frequencies of front vowel resonances so that brightness is more matched across vowels

25. Singers formant • “Singers formant”: extra energy around 3000 Hz (Sundberg says 2300-3000 Hz for basses, 3000-3800 for tenors), which allows a solo voice to stand out against an orchestra, or other singers • Sopranos don’t much need a singers formant against an orchestra, because any note above about B4 will stand out by itself. Similarly for amplified singers.

26. Singers formant • Not an additional formant, but a clustering of F3, F4, F5; when they are close together in frequency their strengths are mutually enhanced and they give one broad strong spectral peak • Male singers: enlarge the ventricle (just above the larynx), lower the larynx • It is not known how altos (or sopranos, if they have one) produce their singers formant

27. Miller: singers formant

28. Example: Fischer-Dieskau (last vowel)

29. Speakers formant • More like at 3500 Hz than 3000 • Property of speaking voices judged to be good • Seen in some singing voices, especially in styles that are more like speaking (e.g. country)

30. Lab 4 and Assn 3: Singers formant • Looking at own voice and at recordings to see if there is a singers formant • trying to increase singers formant in own voice • Emphasized looking at /o/, /u/, where higher formants are expected to be weak so any enhancement will be unambiguous

31. 6. Vowel formants and F0 • Average formant frequencies for different English vowels • a strong soprano voice matches F0 (H1) to F1, while a weak voice has no formant near F0 • [Good illustration of this on DVD: the good voice and the bad voice samples] • Sundberg says that tuning F0 to F1 can add up to 30dB to the sound level • [other strategies in other ranges: Pavarotti’s tenor tuning of F1 to H2 in chest voice, F2 to H3 or H4 on high notes]

32. When F0 is above F1 • F0 > F1 for many soprano notes • F1 cannot match F0, so H1 can’t be boosted by a resonance • vowel qualities are indistinct because F1 is not excited • trained singers tend to adjust the vowel quality so that the F1 moves up, in the direction of F0

33. F1 and F0 • F1 is raised by opening the mouth more, or shortening the vocal tract (e.g. smiling) • YouTube videos of Queen of the Night aria singers and their mouth contortions on the high notes

34. Sundberg: F1 tuning when F0>F1

35. The soprano challenge • A few years ago a study of this effect, explicitly testing what Sundberg had said, got a lot of publicity: http://www.phys.unsw.edu.au/~jw/soprane.html • They found that a trained soprano singing above about 440 Hz tuned every vowel’s F1 to the F0, where formants were determined by reflection

36. Dani and Shri at USC – MRI study of vocal tract adjustments that cause these formant shifts

37. Assn 4: F1 tuning • Happy Birthday when sung from F4 to F5: not a good match between F0s and F1s • Assignment was to write new lyrics that would give a better match to my vowel formants in this key • Full credit for nonsense, but a prize promised for best meaningful lyrics • Some wild-card vowels allowed where F0 was not near any F1 of mine

38. The winner Yay today yay hurray yay today yay is in Today (na-me) is a-age (A-a-age), spring chickin.

39. Lab 5: a total bust • Tried to watch video en masse in CLICC • Had planned to make EGG recordings

40. Guest lecture • Gerry Berke from Head & Neck Surgery on their research on neuromuscular control of F0, on vocal pathology, and on care of the voice

41. 7. Consonants • 2 chapters each in Miller, Nair, on different aspects of consonants in singing • Miller: oral agility for rapid consonant production

42. 7. Consonants • Voiced vs. voiceless consonants • Effects of voiceless consonants on melodic line • Effect of C voicing on vowel F0 • Lyricist’s choice of consonants already affects the song, independent of artist’s interpretation

43. Sondheim lyrics example • Bernadette Peters, Not a day goes by

44. Consonant “resonance” • Nair: More vs less sonorous (vowel-like) consonants (“consovowels”) as seen in the narrowband spectrogram • Consonant duration • Using consonant articulation artistically, e.g. for emotion

45. Example: lyrics + articulation • Bernadette Peters again, 2 clips

46. Example: lyrics + articulation • Melinda Doolittle vs. Gregorian chant

47. Lab 6 and Assn 5: consonants • Listening to, looking at, and making consonants in different ways

48. 8. Vocal warm-ups • Titze explains warm-up exercises in terms of bringing all systems up gradually • Acoustic loading for respiratory warm-up • increase the acoustic loading on the vocal folds with humming, trills, singing into a straw - lets the vocal folds vibrate with more abduction, and with overall lower Ps for an easy start • increase F0 so that Ps must increase • Fun with straws

49. 9. EGG • Ch. 13 in Nair (1999) = “The Use of the Electroglottograph in the Voice Studio” by D. Miller and H. K. Schutte • “one of the primary aims of training the classical singing voice will be to establish the habit of complete and abrupt closure, at least in mezzo forte and forte” • Seeing this in the EGG waveform

50. Falsetto vs chest voice on [i]: little contact in falsetto