Resonance

Question 1

what are the two different types of vibration?

Answer 1

free and forced

Question 2

when does free vibration occur?

Answer 2

free vibration occurs when an object vibrates without interference

Question 3

How is the rate of vibration determined?

Answer 3

mass, tension, length

Question 4

what is resonant frequency?

Answer 4

the rate at which an object vibrates freely

also known as natural frequency

Question 5

when does forced vibration occur?

Answer 5

when the vibrations of one object cause another to vibrate if their RFs are close enough

ex) tacoma narrows bridge
ex) high note shattering glass

Question 6

explain the shattered glass example of forced vibration.

Answer 6

the frequency of the note and the glass match. because they are vibrating at the same rate, constructive interference happens and causes the amplitude to increase

Question 7

what is applied/driving frequency?

Answer 7

the vibration of the original source

ex) singer

Question 8

what is a resonator?

Answer 8

the object that is forced into vibration

ex) glass

Question 9

name some effects of resonance

Answer 9

• make walls buzz

- make speech possible

Question 10

name the 2 types of resonators

Answer 10

mechanical and acoustic

Question 11

what is a mechanical resonator?

Answer 11

does not contain a body of air

ex) tuning fork, wall

Question 12

what is an acoustic resonator

Answer 12

container filled with air

ex) vocal tract, ear canal, mirror, tube

Question 13

what is the relationship between mass and resonant frequency

Answer 13

the bigger an object, the lower is its frequency

Question 14

how do acoustic resonators act as filters in speech?

Answer 14

they exclude certain frequencies while allowing others to pass

this is based on constructive and destructive interference.

Question 15

which frequencies will a resonator amplify?

Answer 15

frequencies at or close to its resonant/ natural frequency

Question 16

which frequencies will a resonator damp/attenuate?

Answer 16

frequencies that are far from its RF/NF

Question 17

what is bandwidth?

Answer 17

the range of frequencies that a resonator will transmit/amplify/respond to

Question 18

A resonance curve shows…

Answer 18

the vibratory response of a resonator to any applied frequency (bandwidth)

Question 19

Some other names for a resonance curve are

Answer 19

transfer function, input-output graph

Question 20

Does a resonance curve show sound

Answer 20

NO it shows the frequency response of a resonator

Question 21

Center Frequency (fc)

Answer 21

Natural frequency-the resonant frequency with the greatest response from the system

Question 22

Upper cutoff frequency (Fuc)

Answer 22

frequency above the Fc where the resonator does not respond

Question 23

Lower cutoff frequency (Flc)

Answer 23

frequency below the Fc where the resonator does not respond

Question 24

low pass filter

Answer 24

all lower frequencies are transmitted

Question 25

high pass filter

Answer 25

all higher frequencies are transmitted

Question 26

band pass filter

Answer 26

all frequencies within a certain bandwidth are transmitted and those outside are damped

Question 27

band stop filter

Answer 27

higher and lower freqs. pass but not those within damps freqs. within bandwidth happens during speech

Question 28

What type of filter is the VT?

Answer 28

band pass filter

Question 29

which cavities is the VT comprised of?

Answer 29

pharynx,oral, and nasal

Question 30

describe the VT as a resonator

Answer 30

VT is a tube which is open at one end (lips) and closed at the other (VF must be closed in order to vibrate)

Question 31

Quarter wave resonator

Answer 31

only one quarter of the wave fits into the tube at any time has multiple resonant frequencies, multiple bandwidths

Question 32

what are resonant frequencies of the VT called?

Answer 32

formants

Question 33

why is the VT called a variable resonator?

Answer 33

because it can assume different shapes (through articulators)

Question 34

Different shapes result in..

Answer 34

different formant frequencies

Question 35

what does the sound filter theory of vowel production explain?

Answer 35

it explains how the sound prodouced at the larynx is modified by changing VT resonances to create different vowels

Question 36

source function

Answer 36

origin of sound, VF vibration doesn't sound like anything but buzzing

Question 37

transfer function

Answer 37

VT resonance response to diff frequencies shown on a resonance curve

Question 38

output function

Answer 38

the sound exiting the oral or nasal cavity

Question 39

which vowel is the SFT based on?

Answer 39

schwa