laryngeal system

time it takes to complete one cycle of vibration; indirect relationship with frequency

measured in cycles per second, Hz; perceptual correlate is pitch

magnitude of vibration measured in dB SPL; perceptual correlate is loudness

temporal relation of sine waves within a complex wave

sine waves add together

sine waves are out of synch and cancel each other out; perfectly out of synch –> silence

comprised of multiple sine waves of different frequencies; human voice

breaks down a complex waves into its sine waves

shows a sine wave; x-axis is time, y-axis is amplitude

shows a sine wave or complex wave; x-axis is frequency, y-axis is amplitude

shows energy of speech; x-axis is time, y-axis is frequency

formants represent peaks; higher fundamental frequency means less spectral density - harmonics are whole number multiples, lower Fo = harmonics closer together, higher Fo = harmonics more spaced out

body of the VF; responsible for subtle pitch changes; isometric function is longitudinally stretching VF to increase pitch, isotonic function is thyroid and arytenoids move in, relaxing TA to decrease pitch

responsible for more dramatic pitch changes via rocking and gliding; pars recta passively stretches TA by rocking; pars oblique passively stretches TA by gliding

adducts the membranous portion of the VF (anterior 2/3); responsible for medial compression, or how tightly the VF close at midline

adduct the cartilaginous portion of the VF (posterior 1/3); 2 muscles - transverse and oblique

abducts the cartilaginous portion of the VF; only laryngeal abductor

uses dental mirror in the back of the throat; pre-technology visualization technique; can see if VF are straight and white (what ENTs care about)

camera/wire through the nose; used for those who cannot tolerate rigid scope; patient can phonate bc camera is not in mouth

done by ENTs for cancer biopsies

first method to see VF actually vibrating; camera pulled film fast then played back slowly

camera hooked up to Fo censor worn by patient; snapped images at different points throughout VF vibration cycle and played back together; with strobe light looked like a continuous cycle

latest technology; independent of Fo, catches VF vibrating and slows it down

VF open with unmodulated airflow when phonation begins