Vocal Fold Vibration

Question 1

Vertical Phase Difference

Answer 1

inferior margins of the vocal folds open first and close first.

superior margins open last and close last

Question 2

Longitudinal Wave

Answer 2

posterior portion of vocal folds open first and close last

anterior portion opens last and close first

Question 3

The goal of VF waves is to

Answer 3

SHAPE the air pressure released by the glottis

Question 4

Describe the 1-Mass Model of VF Vibration

Answer 4

the mass of one VF is represented by a rectangular block.

the spring signifies the recoil force of the VFs

this model fails to fully explain VF vibration because there is a lot MORE movement

Question 5

Describe the 3-Mass Model of VF Vibration

Answer 5

made to overcome the limitations of the 1 mass model.

M=body mass=lateral movements
M1 and M2=cover masses=vertical phase differences

Question 6

Different degrees of adduction result in….

Answer 6

perceptual voice features such as normal, breathy, and pressed vocal quality.

Question 7

What causes a breathy voice?

Answer 7

the folds start vibrating before closure is achieved, full closure is not reached

Question 8

What causes a pressed voice?

Answer 8

very high medial compression forces

Question 9

What is fundamental frequency?

Answer 9

the rate of vibration of the VFs (Fo)

corresponds to perceptual pitch

Question 10

What is the sound source for speech?

Answer 10

laryngeal vibration

Question 11

How long does a single cycle of opening and closing of the VF take?

Answer 11

~1/100th of a second

Question 12

How many times a second does this cycle repeat itself?

Answer 12

100-250 times/sec

depends on male/female

Question 13

What creates the sound we hear?

Answer 13

“puffs of air” that are released during each cycle NOT the impact of the folds coming together

Question 14

What is the glottal spectrum?

Answer 14

the numerous energies that are produced by the vibrating vocal folds….for example harmonics

Question 15

How many harmonics are present in the human voice?

Answer 15

~40

Question 16

If the Fo of an individual’s VFs is 100 Hz, then what energies do the harmonics of the sound-wave created?

Answer 16

100x2=200

100x3=300

Question 17

As Fo increases….what happens to harmonics?

Answer 17

harmonics spread out

Fo=200
200x2=400
200x3=600
200x4=800
....

Question 18

What can enhance or suppress harmonics?

Answer 18

the shape of the vocal tract (acts as a filter)

Question 19

VF do not vibrate in a completely even manner due to..

Answer 19

variations in tissu structure, variations in lung pressures, VF length and symmetry differences

Question 20

What is jitter?

Answer 20

the timing variability between cycles of vibration.

frequencies

Question 21

Which populations have higher jitter values?

Answer 21

children and elderly

Question 22

What is shimmer?

Answer 22

differences in amplitude from one cycle to the next

loudness