Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Acoustics > Exam > Flashcards

Exam Flashcards

1
Q

What is the ratio of a Pythagorean octave?

A

2:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the ratio of a Pythagorean perfect fifth?

A

3:2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the ratio of a Pythagorean perfect fourth?

A

4:3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the ratio of a Pythagorean whole tone?

A

9:8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the ratio of a Pythagorean semi-tone?

A

256:243

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pythagorean tuning is based on stacking which interval?

A

Perfect fifths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Quarter-comma mean tone puts which interval perfectly in tune at the expense of the fifth?

A

Major third

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the first part of an amplitude envelope called?

A

Attack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the general speed of sound at room temperature?

A

343 m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of nodes will you find at the ends of an open-open pipe?

A

Pressure nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the disadvantages of just intonation?

A

It only works with one fundamental (no modulating) and there are two sizes of whole tone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the average frequency range of musical pitch?

A

30-4000 Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the Pythagorean comma?

A

The difference between 7 octaves and 12 pure fifths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which interval is most commonly made out of tune when tempering?

A

Fifths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the ratio of the fifths in 1/4-comma mean tone?

A

1.495

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the “wolf” fifth?

A

The wolf fifth is the fifth that is most out of tune in 1/4-comma mean tone temperament, called the wolf because it “howls”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How big is a cent?

A

1/100 of an equally tempered semitone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the ratio for the equally tempered semitone?

A

1.0595

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What frequency would the A two octaves below A440 be?

A

110 Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a standing wave?

A

A wave that appears to form a stable displacement pattern on a vibrating string (the first mode of vibration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Two pitches (one at 440 Hz and one at 442Hz) will beat at what frequency?

A

2 Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The pitches formed by the harmonic series of a string correspond to which tuning system?

A

Just

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do you find the total displacement pattern of a string?

A

Add all of the component modes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does a two-dimensional spectrum show?

A

Amplitude over frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The approximate displacement pattern of a bowed string has what waveform?

A

A sawtooth wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does the body of the violin do?

A

Radiates and filters the sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How do you calculate frequency?

A

Speed/wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What do convex surfaces do to sound?

A

Scatter the sound outwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is it called when sound waves bend around an object in their path?

A

Diffraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is intensity?

A

The amount of power flowing through a given area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How many times more intense will a sound be at 12m than at 3m distance?

A

16 (3x4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How do you double intensity in dB?

A

double is roughly 3dB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are room modes?

A

The frequency bands favoured by a room

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What do acoustic clouds do in an auditorium?

A

Increase intimacy and ensemble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What 3 things contribute to the frequency created by blowing on a sharp edge?

A

Speed of air flow, sharpness of edge, and angle of airflow

36
Q

What interval do closed pipes overblow at?

A

Twelfth

37
Q

What will a small hole drilled near the middle of a length of pipe do?

A

Allow the second mode to sound more easily

38
Q

What type of waveform does a double reed create?

A

Rectangular

39
Q

How many slide positions does the trombone have?

A

7

40
Q

What is the ratio for a Ptolomaic (or just) semitone?

A

16:15

41
Q

What are the four types of natural oscillators?

A

Springs, strings, air columns, and pendulums

42
Q

What is a node?

A

The point of no vibration

43
Q

What is an antinode?

A

The point of maximum displacement

44
Q

What is a period?

A

The horizontal “distance” of one repetition of a vibration

45
Q

What is the amplitude?

A

The vertical “distance” between the peak & trough of a wave, on the y-axis of a waveform diagram

46
Q

What happens to the amplitude with each successive mode?

A

The amplitude gets smaller with each mode (A=1/m)

47
Q

What is a spectrum showing?

A

Amplitude/Frequency, which frequencies are present and the relative volume of the harmonics

48
Q

What is decay?

A

The dampening of sounds over time

49
Q

What is attack?

A

How quickly a note reaches its maximum amplitude

50
Q

What are transients?

A

The collective of decay, sustain, and attack, which together form the amplitude envelope

51
Q

What is the function of the strings and the body of a violin?

A

The string is the sound producer and the body is the sound amplifier/modifier (a filter of sorts)

52
Q

What is impedence?

A

The resistance to vibration of a particular material. If equal, all energy is transmitted, instantaneous dampening. If very different, vibration lasts and not as much energy transmitted (because there is energy to return along the string)

53
Q

What is the Helmholtz resonance?

A

The fundamental resonance of an enclose space (depends on volume of air and the size of the hole)

54
Q

What are transverse waves?

A

Waves that displace perpendicular to the direction of propagation.

55
Q

What are longitudinal waves?

A

Waves that displace parallel to the direction of propagation (essentially the elasticity of air)

56
Q

What is the approximate speed of sound at room temperature?

A

343 m/s

57
Q

What causes a sonic boom?

A

When a plane’s speed crosses the speed of sound, the Doppler effect creates a sonic boom

58
Q

Are the angle of incidence and the angle of reflection equal to one another?

A

Yes

59
Q

What is reflection?

A

Sound bouncing off of a material, depends on impedence

60
Q

What is absorption?

A

Sound being absorbed by a material, usually more absorption with softer materials

61
Q

What is diffraction?

A

When a sound bends around a solid object

62
Q

What is refraction?

A

A change in medium, such as temperature, that causes a soundwave to bend

63
Q

What is interference?

A

Two sound sources at the same frequency, can be either in or out of phase with each other

64
Q

What is phase?

A

Phase refers to the degree to which two sounds are in sync

65
Q

What is reverberation?

A

Time to decay (less than 60dB), the overall mashup of echoes, depending on the volume of the room, the surface area, and absorption and reflection

66
Q

What is resonance?

A

The shape and size of a room (which affects the preferred harmonics of the room)

67
Q

What is diffusion?

A

Where the waves are scattered, reduces resonance

68
Q

What is intimacy?

A

How close the performer sounds

69
Q

What is ensemble?

A

The level of reflection among players in an ensemble, as players bodies create acoustic shadows and impede sounds from reaching those behind them

70
Q

What is warmth?

A

The reverberation time at low frequencies

71
Q

What is brilliance?

A

The opposite of warmth, reverberation times at higher frequencies

72
Q

What are the 4 types of pipes?

A

Open-open (such as a flute), open-closed (such as a clarinet), conical (such as a sax), and mixed (such as a trumpet)

73
Q

Where are the pressure nodes for lower modes in a trumpet?

A

In the bell (higher outside)

74
Q

Where are the pressure antinodes for higher modes in a trumpet?

A

In the mouthpiece

75
Q

What is unique about the harmonics in a trumpet?

A

The pedal tone (fundamental) is missing because it s severely out of tune

76
Q

What is the pipe shape progression of a trumpet?

A

Cylinder-cone-flare

77
Q

What are the three types of idiophones?

A

Lithophones, made of stones, xylophones, made of wood, and metallophones, made of metal

78
Q

Are the ends of the bar in an idiophone nodes or antinodes?

A

antinodes

79
Q

What is Young’s modulus?

A

The stiffer a thing is, the higher its frequency

80
Q

How do the supports for the bars on an idiophone affect the modes?

A

First mode is promoted, second and third are suppressed (due to forced nodes at the antinode position)

81
Q

How do you tune the bars of an idiophone?

A

Filing the ends heightens the pitch, filing underneath lowers the pitch

82
Q

In idiophones, frequency is proportional to what two other elements?

A

Rigidity and thickness

83
Q

In idiophones, frequency is inversely proportional to what two other elements?

A

Density and length

84
Q

How do you strike a pitched vibrating plate?

A

You must first get the plate speaking as it has a slow attack

85
Q

What shape are the nodes on a bell?

A

Circular nodal lines, concentric around the center of the bell

Acoustics (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions