Module 4 Flashcards
(26 cards)
What do voice problems come from? What does therapy aim to do?
Disordered vocal fold activity. Therapy aims to improve vocal fold movements. Detailed activity about movement of larynx helps with assessment/treatment.
What do Doctor examine larynx with?
Laryngeal mirror- low level detail. Must pull on tongue to tug on epiglottis. Can see if structures growth and movement.
For more detailed voice work, ENT /SLP will use
Rigid scope exam- shows on screen.
Flexible scope exam- through nasal cavity to shine down on larynx from above so people can articulate normally. Usually used in medical setting.
What is high speed filming?
Standard vhs is 30 frames/s
Not clinically practical because of expense and complexity
Was used in pioneering work on physiology
Massive amounts of data-timing issues
What is stroboscopy?
Capitalizes on optical illusion- each illumination is a snapshot, and paste the snapshots together in succession for a “movie”
30 frames/s, folds may oscillate 200x/s
What is very important in stroboscopy?
TIMING. If you want a frozen image, flash occurs at same point in each cycle
If you want slow motion, flashes slightly delayed in successive cycles.
How do we program when to flash during stroboscopy?
Throat microphone helps to know fundamental f to know where vocal folds will be.
What are strobe limitations?
True vocal fold is not seen. F0 must be steady as flashes can’t synchronize if erratic. Severe dysphonia may not be possible.
What is an electroglottograph? When is there more current? Less?
Placed on larynx on surface of neck, current passes from one side to another. Gives a waveform that shows us movement. More current when folds together, less when apart.
In an open phase, where does the egg signal go?
Indirect path around folds. When closed, can go straight through and be stronger.
What does the signal coming from an egg represent? What is important?
Not sound pressure, glottal width, or opening/closing. Represents vocal fold contact area! Changes in vocal fold contact are important.
When does signal strength grow rapidly?
When folds close. Signal strength greatest when fully closed.
What are advantages of egg?
Noninvasive, safe, easy
What is vocal perturbation?
Voice perturbed away from periodic repitition
What is jitter?
Random cycle to cycle differences in duration (f)
What is shimmer?
Random cycle to cycle amplitude differences
What kind of voice will have higher perturbation? How much perturbation do normal voices have?
Hoarse. Will have jitter and shimmer. Minimal -not natural to have none.
How do you define perturbation in the clinic?
Number won’t give diagnosis- use your ears to see if there’s a problem- track progress over time with numbers.
What causes perturbation?
Neurological- Muscle contraction is inherently un smooth, motor neurons take turns firing, overall contraction is the net effect of many minuscule twitches.
Air flow can be turbulent.
Pathological-vocal fold tissue changes- l/r asymmetry, mass lesions, vocal fold swelling, tension abnormalities
How do we look at perturbation in a client?
Use sustained vowels, avoid onsets, offsets. Comfortable intensity level, record live to computer, compare like with like (same vowel/same conditions)
What is tremor?
Tremor- rythmic change in F0 and amplitude. Much slower than cycle to cycle perturbation
What is FM vs Am
Frequency modulation, amplitude modulation- pattern of gradual increase or decrease in F0 spread across many cycles
What goes up with intensity?
F0
In a person with tremor, TA increases SO
Vocal folds increase activation which reduces airflow
