Phonation M6 Flashcards
sound production
- expired air coming to meet these true vocal folds that are found in our larynx
- phonation is how we produce our sound
- caused by true vocal folds being vibrated via expired air acting upon them
- true vocal folds have to ability to abduct (medially compressed position which is anchored upon forces of the muscles) and adduct
vocal attacks
- simultaneous attack - air released as folds compress - most words
- breathy attack - air released B4 folds compress eg ‘ Harry’
- glottal attack - folds compress B4 air is released “I” - all vowels
what do vocal attacks refer to?
- timing in which air hits glottis and vocal cords do something
what happens to the true vocal folds during voicing?
- true vocal folds strengthen, lengthen, abduct and adduct
phonation - vocal cord vibration
- abrupt cessation of airflow that creates the acoustic disturbance heard as our voice
- expired air is the driving force of the speech- manipulate air
nasal cavity, oral cavity, tongue position, articulators all also assist in making these sounds
steps in phonation
- vocal folds are compressed together
- air pressure from trachea rises to exert pressure on the vocal fold - to push them apart
- medial surface of vocal folds seperate at bottom first and return to midline at the bottom first
- vocal folds suck back together - adduct
- then expired air hits bottom part causing them to separate according to force of exhalation
b/c of the Bernoulli effect cause vibration of vocal folds
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”
-for vocal cords - force of air pushes fold apart and negative pressure created pulls them back together
vibration - caused by pressure
- high intraglottal pressure pushes vocal folds away from midline
- elastic recoil of tissue overcomes Pg and lower edges of vocal folds move towards midline - ‘sucked back’
fundamental frequency
- fundamental frequency - rate of vocal fold vibration - expressed in Hertz, cycles/ second
- closest perceptual correlate = pitch
- control of fundamental frequency is primarily vested in the larynx
what determines the fundamental frequency?
- determined by vocal fold stiffness and their effective vibrating mass - STIFFNESS is important
- stiffer the vocal cords the higher rate or
vibrating
- stiffer the vocal cords the higher rate or
- higher vibration higher the pitch- vice versa
mechanism of longitudinal tension
- changing the length and tension of the vocal folds, changes the rate of vocal fold vibration = frequency
- normal phonation produces range of frequencies/ pitches
what are the average for fundamental freq. for males and females?
male is 130 Hz and female is 220 Hz
what mechanism will assist in changing vocal fold stiffness?
the most important mechanism for changing vocal fold stiffness ( and fundamental frequency) is through the external force exerted by the cricothyroid muscles and the internal force exerted through thyroarytenoid muscles (made up of vocalis and muscularis parts)
what are 2 laryngeal mechanisms for changing fundamental frequency?
- medial compression amount can change the effective mass of the vibrating portions of the vocal folds and thereby change fundamental frequency/ pitch
- laryngeal elevation or depression can change vocal fold stiffness and thereby after fundamental frequency/ pitch
raising pitch
- lengthening and tensing the vocal folds increase the frequency of vibration
- stretched (thin) and tense
- increases pitch
- subglottal pressure increases
what muscles aid in raising pitch?
- muscles
- cricothyroid
- posterior cricoarytenoids
- thyroarytenoids
- raising larynx
- thyrohyroid muscles
lowering pitch
- shortening and relaxing vocal folds decreases the frequency of vibration
- short and thick
- decreases pitch
what is involved in lowering pitch?
- muscles
- thyroartenoids
- lowering the larymx
- sternothyroid
what happens to the true vocal folds as pitch in voice gets higher
vocal cords lengthen
possible sounds - breathiness
raspy, weak or airy quality to the voice
possible sounds - glottal fry
the lowest vocal register + produced through a loose glottal closure that permits air to bubble through slowly w a popping or rattling sound of a very low frequency
possible sounds - falsetto
method of voice production used by male singers, especially to sing notes higher than normal range
possible sounds - whisper
voiced sounds like vowel are produced by forcing air through a narrow posterior glottal chink
phonation - development
- during infancy and childhood larynx enlarge and descends within the neck
- fundamental frequency decreases across infancy and childhood in boys and girls
phonation - aging
- cartilages ossify and calcify, muscle atrophy, connective and epithelial tissues change
- glottal configuration may change with age
- overall slowing of movements
phonation - gender
- fundamental frequency is related to vocal fold mass which is related to overall size (mostly height) and angle of thyroid cartilage ( sharper angle in males)
- males have lower FFA than females post puberty
voice disorders
- 7 to 9% of children to 5 t0 6% of adults will have a voice problem
- women are more likely to develop voice problems than men
- certain ppl. are more likely to experience voice problems - occupational voice users( eg. teachers), most at risk - up to 60% experiencing a voice problem at least once during their career
common cause voice disorders
- Vocal misuse/abuse, e.g. young children screaming/yelling; professional voice
users; excessive throat clearing - Nerve damage, e.g. stroke, traumatic brain injury, head and neck surgery
- Trauma, e.g. football injury
- Neurodegenerative disorders, e.g. Parkinson’s Disease, Motor Neuron Disease
- Normal aging process (presbyphonia)
- Gastroesophageal reflux disease (GERD)
- Illnesses, such as colds or upper respiratory tract infections.
- Smoking – laryngeal cancer
what needs to happen for vocal quality to be clear and not raspy?
vocal folds must vibrate together symmetrically and regularly
what is a nasendoscopy?
- examination of the nose, upper airways and Larynx by the use of a small flexible tube (endoscope).
- quick, minor and painless procedure that is usually performed in the clinical setting.
- the procedure includes a small camera passed through the nostril + passed to the back of the nasal cavity towards the pharynx.
- A nasendoscopy can be used to assess vocal function and/or swallowing function.
