W6 phonation Flashcards
phonation
- the production and utterance of speech sounds
- voicing begins when air is pushed from the lungs through the glottis = opening between the vocal folds in the larynx)
sound production
- True vocal folds are being vibrated via expired air acting upon them
- vocal cords are adducted = (bringing folds together for phonation)
- air coming up from the lungs, hitting the glottis area is stopped
- This combines this expired air + vocal folds which produces phonation
Vocal attacks
Simultaneous attack: air released as folds compress (most words)
Breathy attack: air released before folds compress e.g) - Harry
Glottal attack: folds compress before air released e.g) - “I” vowels
phonation process
1) vocal folds are compressed together
2) air pressure from trachea rises, exerting pressure on the vocal fold - to push them apart
3) medial surface of vocal folds seperate at bottom first and return to midline at the bottom first
4) vocal folds suck back together - adduct
5) expired air hits bottom part causing them to separate
Bernoulli effect
‘if volume flow is constant, velocity must increase at an area of constriction, but have a corresponding decrease of pressure at the constriction”
Bernoulli effect - phonation
vocal cords - force of air pushes fold apart and negative pressure created pulls them back together
vibration of vocal fold
high intraglottal pressure pushes vocal folds away from midline
elastic recoil of tissue overcomes lower edges of vocal folds causing them to move towards midline - ‘sucked back’
how do vocal attacks occur
fundamental frequency
- rate of vocal fold vibration
expressed in Hertz, cycles/ second - closest perceptual correlate = pitch
- determined by vocal fold stiffness & effective vibrating mass
vocal fold stiffness
stiffer the vocal cords the higher rate of vibration
therefore, higher pitch
longitudinal tension
changing the length + tension of the vocal folds, changes the rate of vocal fold vibration
mechanism - changing vocal fold stiffness
- external force exerted by the cricothyroid muscles
- the internal force exerted through thyroarytenoid muscles
laryngeal mechanisms - changing fundamental frequency
medial compression = amount can change the effective mass of the vibrating portions of the vocal folds (changes pitch)
laryngeal elevation / depression = can change vocal fold stiffness (FF + pitch)
raising pitch
lengthening + tensing the vocal folds increase the frequency of vibration (stretching & thinning)
what muscles aid in raising pitch
cricothyroid
posterior cricoarytenoids
thyroarytenoids
lowering pitch
shortening and relaxing vocal folds decreases the frequency of vibration (short and thick) (thyroartenoids involved)
possible sounds - glottal fry
- the lowest vocal register
- popping or rattling sound of a very low frequency
possible sounds - whisper
vowels are produced by forcing air through a narrow posterior glottal chink
phonation - aging
cartilages ossify and calcify, muscle atrophy, connective and epithelial tissues change
overall slowing of movements
voice disorders - causes
Vocal misuse/abuse
nerve damage
trauma
illnesses
types of voice disorders
Laryngitis (inflamed larynx)
muscle tension dysphoria
Neurological voice disorders
Management of voice disorders
Can be solved spontaneously (laryngitis)
Can be resolved by voice therapy (muscle tension dysphoria)
Can be lessened by voice therapy