Exam 1

Question 1

What is sound?

Answer 1

-no physical substance
-audible disturbance in a medium caused by a vibrating force
-sound is made by vibration of air particles

Question 2

What are the forces of vibration?

Answer 2

Results from the interplay between elasticity and inertia

Question 3

Elasticity

Answer 3

-the ability to recover from distortion of shape
—makes string go up and down and return to its resting point

Question 4

Inertia

Answer 4

-the tendency of an object to resist any change in motion
-makes string keep going and moving past it’s resting point

Question 5

Friction

Answer 5

-is a damped vibration where an object ceases to vibrate
-causes amplitude of vibration to decrease over time

Question 6

Amplitude

Answer 6

-amount of displacement from equilibrium
-how big the vibration is (m)

Question 7

Frequency

Answer 7

-how fast an object is vibrating (Hz)
-cycles per sec

Question 8

1ms=?sec

Answer 8

.001 sec

Question 9

Period

Answer 9

-amount of time it takes to complete 1 cycle
-1/frequency=____sec

Question 10

Duration

Answer 10

-total amount of time the object vibrates(sec)

Question 11

Phase

Answer 11

Position within a cycle of vibration related to a circle (degrees)

Question 12

Waveform

Answer 12

-waveform=c/f=___m

Question 13

X and Y axis of waveform

Answer 13

X axis: time
Y axis: amplitude

Question 14

X and Y axis of amplitude spectrum

Answer 14

X axis: frequency
Y axis: amplitude

Question 15

X and Y axis of phase spectrum

Answer 15

X axis: frequency
Y axis: phase

Question 16

Simple sounds

Answer 16

-sounds with energy at only one frequency
-waveform looks like a consistent wave
-spectrum only have one dot/ line

Question 17

Complex sounds

Answer 17

-the sun of 2 or more since waves
-phase spectrum doesn’t show anything

Question 18

Periodic sounds

Answer 18

-simple or complex sound that repeats itself over time
-simple periodic: pure tone or sinusoid
Complex periodic: harmonic sound

Question 19

Harmonic series (Fourier series)

Answer 19

-each tone is a harmonic and the full set of harmonics is a harmonic series
-series of pure tones related systematically to F0

Question 20

Fundamental Frequency (F0)

Answer 20

The lowest in frequency and highest in amplitude
-f(n)=f(0)*n

Question 21

Aperiodic sounds

Answer 21

-sounds that do not repeat over time
-no common factor
-transient and noise

Question 22

Transient

Answer 22

Brief sound with a duration of less than one millisecond

Question 23

Noise

Answer 23

Duration is typically longer than one millisecond and amplitude/phase of sine waves are random

Question 24

Vowels and voiced sounds??

Answer 24

-Harmonic series

Question 25

Fricatives??

Answer 25

-Noise

Question 26

B,D,G??

Answer 26

Harmonic and transient

Question 27

P,T,K??

Answer 27

Transient

Question 28

What is pure tone??

Answer 28

Simple periodic

Question 29

What is harmonic series

Answer 29

Complex periodic

Question 30

What is transient and noise??

Answer 30

Complex aperiodic

Question 31

How does sound propagate?

Answer 31

-sound wave propagates through medium; transfer of energy from air molecule to air molecule -air molecules move back and forth over its resting point and disturbs adjacent molecule to transmit away

Question 32

Compression

Answer 32

-high pressure -medium is compressed creating higher than normal density

Question 33

Rarefaction

Answer 33

-low pressure -medium is stretched causing lower than normal density

Question 34

Speed of sound in air and water

Answer 34

Air: 344m/s Water:1400m/s -water is faster

Question 35

Define wavelength

Answer 35

The distance between peaks of a wave -wavelength=c/f

Question 36

Difference between period and wavelength

Answer 36

Wavelength: measure of distance Period: measure of time

Question 37

A compression and rarefaction interfering will…

Answer 37

Cancel out one another

Question 38

Two compressions interfering; 2 rarefactions interfering will….

Answer 38

Reinforce one another

Question 39

Loudness

Answer 39

-a psychological attribute of sound intensity perceptually quantified by a listener

Question 40

Pitch

Answer 40

-a psychological attribute of sound frequency perceptually quantified by a listener

Question 41

Decibel definition

Answer 41

A measure of relative intensity (sound pressure)

Question 42

Threshold of hearing (dB)

Answer 42

0dB

Question 43

Whisper(dB)

Answer 43

30dB

Question 44

Conversation (dB)

Answer 44

60dB

Question 45

Painfully loud sound (dB)

Answer 45

130dB