Week Five Flashcards
Larynx: Intrinsic Parts & EGG
What cartilages provide structural framework for the larynx?
Cricoid, thyroid, arytenoids, and epiglottis
What is the cricoid cartilage?
The foundation
Shaped as a ring at the base of the larynx (broader part faces backwards)
What is the thyroid cartilage?
The shield
Composed of fused plates, forms the Adam’s apple
Allows for the attachment and movement of vocal ligaments and muscles
Ring shaped
What are the arytenoid cartilages?
The vocal adjusters
Pivot and slide on the cricoid, crucial for vocal fold tension and position
What does the movement of the arytenoid cartilages adjust?
Pitch and quality of phonation
Rotate to bring the vocal folds closer and farther apart
What is the epiglottis?
The protective flap
Located above the larynx, acts as a movable flap that covers the glottis to protect the airway
What are the corniculate cartilages?
Sit atop each arytenoid, adding structure to the aryepiglottic folds
Role in maintaining the integrity and function of the upper laryngeal area
What are the posterior cricoarytenoid (PCA) muscles
ABduct the vocal folds by pivoting the arytenoid cartilages, essential for opening the glottis
Vital for breathing and voice modulation
*think: ABduct as in stealing a child, moving away
*think: peace away
*think: P pivot
What are the lateral cricoarytenoid (LCA) muscles?
ADDuct the vocal folds by rotating the arytenoid cartilages inward
Create medial compression necessary for phonation
What are the interarytenoid (IA) muscles?
Comprising of transverse (horizontal) and oblique (x) components
ADDuct to facilitate complete vocal fold closure
Work in tandem with LCA muscles for phonation
*think: I and L look alike therefore work together
*think: aye aye captain (complete closure, not half assed)
What is the aryepiglottic muscle?
Extensions of the IA muscles to connect to the epiglottis, forming aryepiglottic folds
Help protect the airway during swallowing
What is the cricothyroid muscle (CT)
Adjusts tension in the vocal folds, plays key role in pitch modulation
Innervated by the external branch of the superior laryngeal nerve
How does the cricothyroid muscle adjust pitch?
When contracted it moves in a hinging motion to pull the thyroid forward which will increase tension and pitch
What is a process?
Pointy projection
What is Ferrein’s string theory?
Proposed that vocal folds vibrate like the strings of a violin
Sound production relies on string like oscillation
Doesn’t make much sense
What is the neurochronaxic theory?
Proposed each vocal fold vibration is controlled by neural activation
Challenge: body cannot send signals that fast (refractory period)
What is Bernoulli’s principle?
Within a liquid or gas, there’s an inverse relationship between pressure and velocity
How does Bernoulli principle relate to vocal fold vibration?
Air increases in velocity as it passes between vocal folds which decrease pressure on side walls
Reduced pressure pulls vocal folds towards each other causing the closure
Then pressure below builds up forcing them apart
Cycle repeats
What does EGG stand for?
Electroglottography
What does EGG measure?
Non-invasive
Measures vocal fold contraction during phonation
Assesses voice quality, phonation types, and vocal fold behaviour
What do EGG waveforms represent?
Degree of contact between the vocal folds
How does EGG work?
As vocal folds come together, impedance decreases, resulting in higher waveforms
When vocal folds are apart, impedance increases, and waveform values drop
*think: when you’re together, less impatient = higher review but when apart, more impatient = lower review
How do you identify the opening peak of an EGG?
Lower waveform values indicating vocal folds separation
What does the slope of a waveform in EGG indicate?
How quickly vocal folds open and close (opening and closing speed)
What is a DEGG?
Derivative of raw EGG
Clearly shows the opening and closing peaks
What is the open quotient (OQ) in EGG?
Ratio representing the opening phases duration in one signal
Larger in breathy voicing, smaller in creaky voicing
What is the close quotient (CQ) in EGG?
Ratio representing the closed phase duration in one cycle
What do regular vs irregular vibration indicate in EGG?
Regular: normal phonation
Irregular: may indicate vocal pathology
How is modal phonation indicated in an EGG?
Regular waveform with distinct closed and open phases
How is breathy phonation indicated in an EGG?
Reduced peaks in raw signals, indicating less vocal fold contact
Higher OQ than in modal
How is creaky phonation indicated in an EGG?
Higher peaks in raw signals, longer closed phase
Lower OQ than modal
What are some application of EGG in speech research?
Analyzing and diagnosing voice disorder
Analyzing differences in phonation between segments/language’s
Studying the effects of vocal training and therapy
Researching the biomechanics of voice production
What are some advantages of using EGG?
Non-invasive and safe for subjects
Provides direct measure of vocal fold contact dynamics, compared to acoustic signals
