170 likes | 231 Views
Physics 1251 The Science and Technology of Musical Sound. Unit 3 Session 31 MWF The Fundamentals of the Human Voice. Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice.
E N D
Physics 1251The Science and Technology of Musical Sound Unit 3 Session 31 MWF The Fundamentals of the Human Voice
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice What is the frequency of a palm pipe at 20 C that is 500 mm long and has an internal diameter of 35 mm? What are the first three audible harmonics? A palm pipe is a stopped cylinder. Therefore f 1= v/4L′; L′ = 0.500 m+ 0.3 (0.035 m) = 0.5105 f 1= 343/4(0.511) =85.75/0.511 =168 Hz. [E 3 +33¢] f3 = 3f1 = 3 (168) = 504 Hz. [B4 + 35 ¢] f5 = 5f1 = 5 (168) = 840 Hz. [G5 ♯ + 19 ¢]
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice 1′ Lecture: • The vocal folds, located in the larynx, produce vibrations in the vocal tract. • The vocal tract is a stopped air column approximately 17 cm long. It resonates at a fundamental frequency of about 500 Hz. • The shape of the vocal tract provides an acoustic filter of the harmonics produced by the vocal folds.
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Anatomy of the Human Voice 80/20The vocal tract is the instrument of the human voice. Vocal Tract: • Lungs—source of air Pharynx • Trachea—wind pipe • Larynx—voice box Larynx Trachea • Pharynx—mouth and nose Lungs
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Anatomy of the Human Voice 80/20The sound of the human voice originates in the larynx. Larynx Larynx
Closed Open Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Anatomy of the Human Voice 80/20The larynx (or voice box) contains the vocal folds. Vocal Folds Larynx
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Anatomy of the Human Voice 80/20The vocal folds rapidly open and close, introducing pulsations of air into the vocal tract. Vocal Folds Lower Vocal Tract
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Anatomy of the Human Voice 80/20The vocal folds rapidly open and close, introducing pulsations of air into the vocal tract. Vocal Folds Lower Vocal Tract
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Video of Laryngoscopy
Phonation Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice The Vocal Folds--Function 80/20The vocal folds are controlled by muscle and actuated by air moving between them, closing due to the Bernoulli Effect, opening by tension. When flow is interrupted folds open. Air Flow Vocal Folds
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice The Vocal Folds 80/20The pressure waveform produced by the action of the vocal folds is an asymmetrical sawtooth, rich in harmonics. 80/20The fundamental frequency of the voice is determined by the properties of the vocal folds, not the vocal tract. Vocal Folds snap open are pulled shut by air flow are pulled shut by air flow are pulled shut by air flow are pulled shut by air flow are pulled shut by air flow
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice v =343 + 0.6(37-20) =353 m/s Resonances of Vocal Tract ~500 Hz ~1500 Hz L≈ 17 cm ~2500 Hz f1 = v/4L = 353/(4 ‧ 0.17) = 519 Hz f3 = 3f1 , f5 = 5f1 … 80/20The Vocal Tract is a “lossy” stopped pipe ~17 cm long with a fundamental frequency of ~500 Hz.
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Formants of Vocal Tract Amplitude Formant L≈ 17 cm Frequency f1 = v/4L = 353/(4 ‧ 0.17) = 519 Hz f3 = 3f1 , f5 = 5f1 … 80/20The Vocal Tract filters the spectrum generated by the vocal folds; the frequency filter is called the Formant.
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Speech • 80/20The individual units of speech are called phonemes. • The classes of (English) phonemes are: • Unvoiced Plosives‒ p, t, soft k (c, q, x) • Voiced Plosives‒ b, d, g • Fricatives‒ f, v, th • Sibilants‒ s (c) , z, sh, zh, j • Liquids‒ l, r • Nasals‒ m, n, ng • Semi-vowels‒ w, y • Vowels‒ a, e, i, o, u
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Spectrogram of Human Speech
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice 80/20The shape of the Vocal Tract determines the frequency of the Formants. “ah” “eh” “oh” “oo”
Physics 1251 Unit 3 Session 31 The Fundamentals of the Human Voice Summary: • The vocal folds, located in the larynx, produce vibrations in the vocal tract. • The vocal tract is a stopped air column approximately 17 cm long, that resonates at ~500, 1500 and 2500 Hz. • The shape of the vocal tract provides an acoustic filter, called the formant, that modifies the amplitude of the harmonics produced by the vocal folds.