PH 105 Dr. Cecilia Vogel Lecture 14

OUTLINE  consonants  vowels  vocal folds as sound source  formants  speech spectrograms  singing

Vocal Sound Production  Sources of sound:  vocal folds  lips  tongue  teeth  palate  glottis  Sound radiated  though mouth  and/or nose

Types of Consonants  Plosive  air flow is stopped then  example p is plosive with  k is plosive with  Fricative  air flow is restricted and turbulent, “windy”  h is ________ fricative  Spanish has a bilabial (lips) fricative  Both are noise-like in waveform and spectrum

Types of Consonants  Nasals  the sound radiator is the nose  example m, n  Semivowels and liquids are similar to vowels  Semivowels are quick vowel sounds  __, __  Liquids have restricted air flow, but not turbulent (not windy)  __, __

Types of Consonants  Voiced vs. unvoiced  In a voiced consonant,  the vocal folds are vibrating  can have a  In an unvoiced consonant  the vocal folds are  Compare for example   feel vocal fold vibration

Vowels  The sound of vowels (and to some extent consonants)  is due to three factors:  the source of the sound  the resonating cavities  the radiating opening  mainly the mouth for vowels  See table 15.1 for vowel notation  for example, /i/ is long e sound

Vowel Sound Source  Vocal fold vibration is the source of sound for vowels  produces a fundamental and many harmonics  control the  determines the  alone, the sound is buzzy  like a sawtooth wave  contains all harmonics (fig 7.11c)

Resonating Cavities  Cavities in the vocal tract  act as filters of the vocal fold buzz,  increasing the loudness of some frequencies which resonate  filtering out freq’s which don’t.  fig 15.9

Vocal Tract  The vocal tract is complex:  Nasal cavity can be connected or separated by use of  not used much for English vowels (French).  Vocal tract can be thought of as a tube  about 17 cm long  ____ at the vocal fold end, ____ at the lips  Resonances of such a tube  f n = ( nv )/(4 L ), n must be  not odd harmonics of vocal folds!

Recall Impedance  A reflection can occur any time there is a change in impedance, so there can be resonance in each part of a complex tube.  f n = ( nv )/(4 L ), for L 1, L 2, and L 3  Mouth cavity can be made a different L1L1 L2L2 L3L3

Say Ah  For /a/, the mouth is wide  Fig shows double tube that may resonate.  Of all the freq’s produced by vocal folds,  those near 730 Hz, 1090 Hz and 2440 Hz  These resonances are called  the formants of the vowel /a/

Other vowels  In the vowel sound /e/, the mouth is narrow,  a double tube like that two slides ago works here.  producing formants like table 15.3  In /u/, there are constrictions at the back of the mouth and at the lips,  a double __________________ model works here.  producing formants like table 15.3

Recall Spectrograms  Spectrograms  x-axis is time  y-axis is frequency  amplitude is shown by heaviness of graphing

Speech Spectrograms  Observe in fig 16.3  fundamental freq of vowel  very short period on graph  formants of vowels  freq’s that are  /i/ expected to have 270, 2290, 3010  _____ spectra of plosive (c) and fricative (s)  distinguished by  changes with time  /i/ formants rise, then fall into /u/ formants

Singing  Singing differs from speaking.  Pay more attention to  ______ tone (more like sine wave)  Match formant to __________, so it is very strong.  Formants not at fundamental are minimized.  Makes vowels  Singer’s formant at about 3kHz  adds brilliance to lower voices  adds loudness, as it

Summary  Consonants  plosives and fricatives noise-like  plosive has stopped air  semivowels and liquids are vowel-like  Vowels (and vowel-like consonants)  have pitch — fundamental freq  distinct formants — harmonics that resonate  resonances produced by parts of vocal tract  Can read all that off spectrogram  Singing: purer, less articulated, singer’s formant