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1

What is the source sound created through?

vocal fold vibration

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2

If vocal folds are tighter the vibration and pitch is what?

vibration is faster and pitch is higher

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3

Myoelastic aerodynamic theory of vocal fold vibration…

vf adduction through muscular contraction

build up subglottal (aka tracheal) pressure

when Ps is higher than Patm (pressure differential) and the Ps exceeds the glottal resistance, then

vfs will be blown apart air flows through the folds and will be proportional to driving pressure, then

vfs will recoil to midline and be sucked toward the midline by the Bernoulli effect

cycle starts over at 2. (no muscular contraction)

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4

Air flow through glottis as a function of time

area

airflow

pressure

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5

Area

area proportional to width of glotis/distance between vfs

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6

Air flow

air flow proportional to width of glottis/distance between vfs

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7

Pressure

pressure high/flow low

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8

What is the nature of the signal generated by the vibrating vfs?

glottal airflow is proportional to glottal area

glottal airflow can be obtained by inverse filtering of the acoustic signal while glottal area is difficult to obtain.

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9

glottal air flow is _____ to glottal area

proportional

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10

How can glottal airflow be obtained?

by inverse filtering of the acoustic signal while glottal area is difficult to obtain

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11

What would a fourier analysis of airflow signal yield?

A fourier analysis of airflow signal would yield a glottal source spectrum

f0=H1

roll off = -12dB

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12

The waveform of glottal airflow repeats over time is equal to

periodic

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13

If the period of the glottal airflow waveform is known what can be calculated?

F0 can be calculated

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14

Low F0 >

harmonic more dense

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15

High F0 >

harmonics less dense

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16

If the period of a glottal waveform is 4 ms, what is the F0?

250 Hz

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17

Since the glottal waveform is derived from the vibratory pattern of the vocal folds, what happens to the period?

the period of each successive cycle is not exactly the same

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18

How do we refer to the signal created by vocal fold vibration?

quasiperiodic

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19

What is the tilt?

steepness as determine by roll off

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20

What does the tilt of the glottal spectrum give us info about?

the vibratory pattern of the vocal folds

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21

When the glottal airflow is 0 the vfs are____

closed

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22

During a typical vibratory cycle the glottis is open approx. _____ of the cycle and closed approx. _______ of the cycle__

open 60%

closed 40%

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23

If the vocal folds close more slowly, the time the glottis is open is ____ yielding a steep tilt of the glottal source spectrum

longer

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24

If the vocal folds snap together quickly the time the vocal folds are apart is _____ yielding a shallow tilt of the glottal source spectrum

shorter

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25

The steepness of the amplitude decline in the source spectrum is related to what?

how quickly the vfs recoil

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26

What is hyper function?

the vfs are over performing due to rapid forceful closing > less tilt > too much energy in higher frequency

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27

What is the result of a hyperfunction voice?

pressed strained voice

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28

What is hypofunction?

the vfs are underperforming due to slow or incomplete closing of vocal folds > more tilt ? very little energy in higher frequencies

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29

What is the result of a hypofunction voice?

breathy weak voice

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30

What is dysphonia?

abnormal voice quality

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31

Four different acoustic measure of vf function that are informative about voice pathologies…

fundamental frequency

jitter

shimmer

harmonic to noise ratio (HNR)

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32

What is fundamental frequency in vfs?

acoustic correlate of vf vibratory cycles per second

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33

What is mean f0 for boys ages 6-10?

226 Hz

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34

What is the mean f0 for girls ages 6-10?

238 Hz

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35

What is the mean f0 for males?

106 Hz

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36

What is the mean f0 for females?

193 Hz

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37

What does jitter measure?

measures the cycle to cycle variations in vocal periods (frequency)

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38

Jitter is the acoustic correlate of erratic _____

vibratory patterns

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39

Jitter clinically correlates with what?

clinically it correlates somewhat with perceived roughness, hoarseness, and overall severity of dysphonia

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40

What does a typical human exhibit in jitter

jitter levels around 1% or less

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41

What does shimmer measure?

measures the cycle to cycle variations in peak amplitude (amplitude)

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42

What is the acoustic correlate of shimmer?

acoustic correlate of noisy, breathy voice, and overall severity of dysphonia

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43

The reference values for shimmer?

shimmer tends to be higher if vocal fold pathology is present, such as for example vocal nodules

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44

What does harmonic to noise ration compare?

compares the amplitude of the periodic portion to the amplitude of the aperiodic portion of the signal

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45

The _____ the HNR the more noise exists in the voice

lower

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46

What is the acoustic correlate of HNR?

acoustic correlate of breathiness and hoarseness

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47

What is HNR in children?

2 to 2.5 dB

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48

What is HNR in adults?

7 to 19 dB

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49

What are sonorant sounds?

vowels, approximants, nasals

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50

In order to model the resonance frequencies of sonorant sounds we assume what?

a tube model closed at one end and open at the other

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51

What impacts resonance frequencies?

length of the tube, speed of sound, and the shaped of the tube

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52

What does rounding do?

lengthens the vocal tract

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53

what are the three kinds of filters?

high pass

low pass

band pass

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54

What kind of filter creates a resonance?

bandpass filters

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55

Formant frequencies are the _____ frequencies of the vocal tract

resonance

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56

Acoustically the vocal tract can be represented as a system of _______ with the formant frequencies as center frequencies

band pass filters

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57

In addition to the filter function, the acoustic output is also determined by what?

the lip radiation effect

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58

What is the highest octave frequency?

4000 Hz

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59

What does the lip radiation effect provide?

a +6 dB/per octave boost

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60

The lip radiation effect provides a +6 dB/per octave boost because…

the air particle vibration is pressurized as they exit the narrow lip opening

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61

The lip radiation effect is the strongest in…

upper frequencies

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62

We use the source filter theory to predict what?

the formant frequencies for schwa-no major constrictions

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63

Although the vocal tract is open for all vowels, different constrictions occur at different _____ locations of the vocal tract

locations

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64

What is the vocal tract filter also known as

vocal tract transfer function

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65

When does the vocal tract filter change?

changes when the position of the tongue within the vocal tract changes

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66

The tube open at one end is now the ____

front cavity

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67

The back cavity and the constricted area together form a _____

helmholtz resonator

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68

The resonances of the back cavity (helmholtz resonator) can be calculated using the forula of a tube that ___ at _____ ends

closed at both

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69

How can the resonances of a back cavity be calculated?

Fn= nc/2L

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70

What is the equation to calculate the first formant of a Helmholtz resonator?

F1= (1x34000 cm/s)/2xL

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71

If the length of a tube decreases, the resonance frequency ______

increases

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72

If the length of the tube increases the resonance frequency _____

decreases

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73

In a tube that is open at one end and closed at the other a sound wave traveling in this type of tube will bounce off the closed end and what?

Reflect

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74

When a tube is open at one end and closed at the other sounds what at the open end because of an impedance difference?

sounds will reflect back

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75

When the incident wave and its echoes (reflected wave) interact they produce what?

Standing wave

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76

A different way to model the effect of constrictions at different locations along the vocal tract is what?

Perturbation theory

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77

Perturbation theory looks at the ways in which ___ and ___ velocity change as result of constriction location

pressure and velocity

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78

What does pressure =

movement

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79

What does velocity =

fast or slow

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80

When pressure is at its maximum the velocity is ____

zero

i.e. air molecules don’t move

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81

When velocity is at its maximum air pressure is ____

zero

air molecules are free to move to their fullest potential

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82

What do resonance frequencies depend on?

the length of the tube

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83

If the tube is _____ at a place where either pressure or velocity are at a maximum or minimum the resonance frequency changes in predictable ways

narrower

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84

Constriction at a pressure maximum raises what?

the frequency of the resonance (formant)

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85

If constriction is at a pressure maximum (velocity=0) air molecules are what?

forced further away from their rest position

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86

When air molecules are forced further away from their rest position because constriction is at a pressure maximum what increases and raises frequency?

it increases stiffness which in turn raises frequency

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87

Constriction at a velocity maximum lowers what?

the frequency of the resonance

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88

When air molecules encounter a constriction they speed up which lowers what?

resonance frequency

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89

If the constriction occurs at a point that is neither pressure nor a velocity maximum the frequency increases or decreases depending on what?

velocity and pressure values at that point of constriction

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90

In our tube model only ____ the of wave length yields the first resonance of the tube.

1/4

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91

The unconstricted vocal tract serves as reference

F1= _____Hz

F2= _____ Hz

F3= _____Hz

500 Hz

1500 Hz

2500 Hz

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92

The first formant has relatively low pressure, therefore, relatively ___ ____

high velocity > F1 lower than schwa

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93

The second formant pressure maximum (zero velocity) > _____

F2 higher than schwa

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94

Third formant relatively high pressure, therefore realtively low velocity > ____

slightly higher than schwa

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95

What is the source in the source filter theory?

larynx

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96

What is the filter in the source filter theory?

vocal tract

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97

How do we classify vowels?

height

frontness/backness

lip rounding

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98

Who derived general rules that relate the acoustic output of vowel production to articulatory parameters?

Steven and House (1963)

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99

F1 is _____ correlated to tongue height

Negatively

the higher the tongue the lower the F1

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100

F2 is _______ correlated with tongue advancement

positively

the more front the vowel, the higher the F2

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