Quiz 8

Question 1

What is the source of noise for voiceless fricatives?

Answer 1

Place of articulation

Question 2

What type of flow occurs in fricatives?

Answer 2

Turbulent flow

Question 3

Whats the difference between turbulent and laminar flow?

Answer 3

Turbulent (fricatives): chaotic
Laminar (approximates and resonants): uniformed

Question 4

What are some factors that affect turbulence?

Answer 4

Particle velocity, volume velocity, constriction size, and pressure

Question 5

Whats the equation for Reynolds Number?

Answer 5

uL/v
u = flow rate
L = pipe width
v = viscosity

Question 6

What relationship does each element have in effect to Reynolds number?

Answer 6

u = flow rate, if increased, Re will also increase
L = pipe width, the more narrow, the more turbulence
v = viscosity, if increased, Re will decrease (inverse relationship)

Question 7

What is the critical value in speech?

Answer 7

Re(crit) = 1700

Question 8

What does a value higher or lower than Re(crit) predict?

Answer 8

Re > 1700 predicts turbulent flow
Re < 1700 predicts laminar flow

Question 9

What are the turbulence types in fricatives?

Answer 9

Channel turbulence
Obstacle turbulence
English sibilants have both

Question 10

What is particle velocity?

Answer 10

The rate of change of position or mean velocity of flow at any particular place/time (cm/s or mph)

Question 11

What is volume velocity?

Answer 11

Volume flow or discharge rate
Volume of air discharged or passing through the vocal tract in unit time (cm3/s)

Question 12

If volume velocity is kept constant what does particle velocity depend on?

Answer 12

Cross-sectional area
Particle velocity will increase with the decrease in the cross-sectional area

Question 13

What is amplitude primarily determined by in fricatives?

Answer 13

Particle velocity
The narrower the channel, the higher the particle velocity, the louder the sound

Question 14

What is the relationship between closure and amplitude in oral fricatives?

Answer 14

The smaller the closure, the louder the fricative

Question 15

What is the source for fricatives?

Answer 15

Voiceless fricatives: channel and/or obstacle turbulence plus place of articulation
Voiced fricatives: channel and/or obstacle turbulence plus vocal fold vibration

Question 16

What is the filter for fricatives?

Answer 16

Part of the vocal tract in front of the constriction
also important are the sublingual cavity and the lip configuration