electroglottography Flashcards
what does EGG measure?
vocal fold contact during phonation
what does the waveform provided by EGG represent?
the degree of contact between the vocal folds
how is EGG useful?
useful in assessing voice quality, phonation types, vocal fold behaviour
T/F: EGG gives you direct information
true
where to place the electrodes?
on both sides of thyroid cartilage; the closer they are, the better
what exactly does EGG record?
the electrical impedance across the larynx
as vocal folds come together, impedance ___, resulting in ____ waveform values
decreases; higher
when vocal folds are apart, impedance ___, resulting in ____ waveform values
increases; lower
characteristics of EGG waveform
closed phase, open phase, opening and closing speed
what makes a full cycle in EGG waveform?
closed phase and open phase
at closed phase, what are the waveform values and what do they indicate
higher waveform values indicate vocal fold contact
at open phase, what are the waveform values and what do they indicate
lower waveform values indicate vocal folds separation
where is the opening peak in EGG waveform?
right when closed phase changes to open phase
how does closing peak occur and what does it represent?
closing peak happens suddenly where vocal folds snap together
where is the steepest slope?
closing peak
what tells us about the slope of the waveform?
opening and closing speed
what does the slope of the waveform tell us about the vocal folds?
indicates how quickly vocal folds open and close
the closing peaks are __ and the opening peaks are ___
positive, negative
open quotient (OQ)
ratio of open phase relative to whole duration of one cycle (always between 0 & 1)
closed quotient (CQ)
ratio of close phase relative to whole duration of one cycle
regular patterns of vibration suggest ____ phonation
normal
irregular vibration patterns may indicate ___ ______
vocal pathology
when there is a greater distribution of values, what does this mean for contact between vocal folds?
greater contact?
