1. SPEECH PRODUCTION

MUSIC 318 MINI-COURSE ON SPEECH AND SINGING

Science of Sound, Chapter 15The Speech Chain, Chapter 4The Science of the Singing Voice (Sundberg, NIU Press, 1987)

THE VOCAL ORGANS

VOCAL TRACT WITH SOFT PALATE

LOWERED FOR BREATHING

BREATHING AND AIR FLOWLUNGS HAVE NO MUSCLES ; BREATHING IS ACCOMPLISHED BY CHANGING THE SIZE OF THE CHEST CAVITY IN TWO WAYS:1.DOWNWARD MOVEMENT OF THE DIAPHRAGM TO LENGTHEN THE CHEST CAVITY2. ELEVATION OF THE RIBS TO INCREASE THE FRONT-TO-BACK THICKNESS

TWO MUSCLE GROUPS ARE USED:1. EXTERNAL AND INTERNAL

INTERCOSTALS THAT EXPAND AND CONTRACT THE RIB CAGE

2. ABDOMINAL WALL AND DIAPHRAGM WHICH CHANGE THE ABDOMINAL CAVITY

BREATHING TECHNIQUES

SINCE BREATHING IS DONE WITH 4 MUSCLES, THERE ARE SEVERAL DIFFERENT TECHNIQUES THAT CAN BE USED (SUNDBERG, 1987)

“BELLY IN” TECHNIQUE: THE EXPIRATORY INTERCOSTAL AS WELL AS THE DIAPHRAGM MUSCLES ARE STRETCHED AND CAN THUS BE EFFICIENTLY RECRUITED IN ORDER TO PROMPTLY INCREASE SUBGLOTTAL PRESSURE. “BELLY OUT” TECHNIQUE: IF COMBINED WITH ELAVATED AND OUTWARD POSITIONING OF THE RIB CAGE WALL, THE INTERCOSTAL MUSCLES ARE STRETCHED, AS ARE THE ABDOMINAL WALL MUSCLES, BUT INSPIRATORY EFFORTS ARE LIKELY TO BE NEEDED.

SUBGLOTTAL PRESSURE

SUBGLOTTAL PRESSURE GENERALLY REFERS TO “OVERPRESSURE,” THE AMOUNT BY WHICH THE PRESSURE BELOW THE GLOTTIS EXCEEDS ATMOSPHERIC PRESSURE.

THE MOST ACCURATE WAY TO DETERMINE SUBGLOTTAL PRESSURE IS TO INSERT A THIN NEEDLE INTO THE TRACHEA, AND A FEW SPEAKERS AND SINGERS HAVE SUBMITTED TO THIS METHOD.

AN INDIRECT METHOD IS TO CLOSE THE LIPS AND OPEN THE GLOTTIS, SO THAT MOUTH PRESSURE IS ESSENTIALLY EQUAL TO SUBGLOTTAL PRESSURE. THEN THE SUBGLOTTAL PRESSURE CAN BE DETERMINED BY THE DROP IN ORAL PRESSURE DURING THE PRODUCTION OF THE CONSONANT /p/.

SUBGLOTTAL PRESSURE DURING PHONATION

SUBJECT ASKED TO TAKE A DEEP BREATH AND COUNT FROM 1 TO 32.TO THE LEFT OF THE VERTICAL LINE, THE NET MUSCULAR FORCE IS INSPIRATORY; TO THE RIGHT IT IS EXPIRATORY.

THE SUBGLOTTAL PRESSURE Ps REMAINS REASONABLY CONSTANT THROUGHOUT THE ENTIRE PROCESS. (SUNDBERG, 2007).

SUBGLOTTAL AND ORAL PRESSURE AND AIR FLOW

AIR FLOW, SUBGLOTTAL , and oral PRESSURE VARIATION WHILE SPEAKING THE PHRASE “phonetic aspects”

THE LARYNX

(a) BACK VIEW

(b) SIDE VIEW

VOCAL FOLDS CONTROL OF THE GLOTTAL OPENING BY THE ARYTENOIDS

VOCAL FOLD VIBRATIONS

GLOTTOGRAMS (GLOTTAL FLOW WAVEFORMS)

SHOW HOW THE AIR FLOW THROUGH THE GLOTTIS VARIES WITH TIME

GLOTTAL MASK WITH INVERSE FILTERING

SUBJECT PHONATES THROUGH AN ACOUSTIC RESISTANCE, SO THAT MICROPHONE MEASURES GLOTTAL FLOW

INVERSE FILTER HAS A TRANSFER FUNCTION THAT IS THE INVERSE OF THE VOCAL TRACT TRANSFER FUNTION . THUS IT MINIMIZES THE EFFECT OF THE VOCAL TRACT AND DISPLAYS THE GLOTTAL FLOW AS IF THERE WERE NO VOCAL TRACT.

GLOTTAL WAVE FORM SPECTRUM

THE FLOW OF AIR THROUGH THE GLOTTIS IS ROUGHLY PROPORTIONAL TO THE AREA OF THE GLOTTAL OPENING. FOR NORMAL PHONATION, THE TRIANGULAR WAVEFORM OF THE GLOTTAL FLOW IS COMPOSED OF HARMONICS THAT DECREASE AS 1/n2 (AT A RATE OF -12dB/OCTAVE.

FLOW GLOTTOGRAM AND ITS DERIVATIVE

DERIVATIVE SHOWS THE RATE OF CLOSURE OR OPENING OF THE GLOTTIS

(WIGGLES ARE AN ARTIFACT DUE TO IMPERFECT INVERSE FILTERING)

GLOTTOGRAMS FOR LOUD AND SOFT PHONATION

LOUD PHONATION REQUIRES A RAPID CLOSURE OF THE GLOTTIS

GLOTTOGRAMS FOR DIFFERENT MODES OF PHONATION

GLOTTOGRAMS FOR MODAL AND FALSETTO SINGING

SOURCE/FILTER MODEL OF SPEECH

THE SOURCE/FILTER MODEL DESCRIBES SOUNDS OF SPEECH AND SINGING AS A PRODUCT OF SOURCE AND FILTER AND RADIATION EFFICIENCY

SPEECH SOUND=SOURCE x FILTER x RADIATION EFFICIENCY

IF EACH OF THESE QUANTITIES IS EXPRESSED IN DECIBELS (dB), THEN THE CONTRIUBTIONS ARE ADDED RATHER THAN MULTIPLIED.

THE SOURCE FUNCTION DECREASES IN STRENGTH ABOUT 12 dB/OCTAVE. THE RADIATION EFFICIENCY OF THE MOUTH RISES ABOUT 6 dB/OCTAVE, SO THE NET DECREASE DUE TO THE 1ST AND 3RD TERMS IN THE EQUATION IS ABOUT 6 dB/OCTAVE

WAVEFORMS AND SPECTRA OF TWO VOWELS

/a/ (ah)

/u/ (uh)

VOWELS OF AMERICAN ENGLISH