Unit #1 Test Vocabulary

Question 1

Sound

Answer 1

Vibrations that travel through a medium and can be heard when they reach a person’s or animal’s ear.

Question 2

Vibration

Answer 2

A rapid back and forth motion.

Question 3

Medium

Answer 3

A substance through which sound waves can travel (e.g., air, water, solid).

Question 4

Eardrum

Answer 4

A membrane in the ear that vibrates in response to sound waves.

Question 5

Pressure Wave

Answer 5

A wave characterized by the movement of particles in the medium in which the wave is traveling.

Question 6

Audible

Answer 6

Sounds that can be heard by the human ear.

Question 7

Inaudible

Answer 7

Sounds that cannot be heard by the human ear.

Question 8

Infrasonic Waves (Infrasound)

Answer 8

Sound waves with frequencies below 20 Hz.

Question 9

Ultrasonic Waves (Ultrasound)

Answer 9

Sound waves with
frequencies above 20,000 Hz.

Question 10

Sonogram

Answer 10

An image formed using ultrasound.

Question 11

Propagation

Answer 11

The movement or spreading of sound waves through a medium.

Question 12

Compression

Answer 12

A region in a longitudinal wave where the particles are closest together.

Question 13

Rarefaction

Answer 13

A region in a longitudinal wave where the particles are furthest apart.

Question 14

Wavelength

Answer 14

The distance between two consecutive
compressions or rarefactions in a sound wave.

Question 15

Amplitude

Answer 15

The maximum extent of a vibration or oscillation, measured from the position of equilibrium.

Question 16

Frequency

Answer 16

The number of waves that pass a point in a certain period of time.

Question 17

Hertz (Hz)

Answer 17

Unit of frequency, defined as one cycle per second.

Question 18

Decibel (dB)

Answer 18

A unit used to measure the intensity of a
sound.

Question 19

Pitch

Answer 19

The quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of
a tone.

Question 20

Timbre (Tone Color)

Answer 20

The character or quality of a musical
sound or voice as distinct from its pitch and intensity.

Question 21

Dynamics

Answer 21

The volume of a sound or note.

Question 22

Echo

Answer 22

A sound that is reflected off a surface and heard again.

Question 23

Longitudinal Wave

Answer 23

A wave in which the movement of the
medium’s particles is parallel to the direction of the energy transport.

Question 24

Mechanical Wave

Answer 24

A wave that requires a medium through
which to travel.

Question 25

Transverse Wave

Answer 25

A wave in which the motion of the
medium’s particles is perpendicular to the direction of the wave’s travel.

Question 26

Shockwave

Answer 26

A type of pressure wave formed when an object moves faster than the speed of sound.

Question 27

Resonance

Answer 27

An increase in amplitude that occurs when a periodic force is applied at the natural frequency of an object.

Question 28

Harmonics

Answer 28

Frequencies at which an object will naturally vibrate.

Question 29

Acoustics

Answer 29

The science of sound, including its production, transmission, and effects.

Question 30

Sound Intensity

Answer 30

The power carried by sound waves per unit area in a direction perpendicular to that area.

Question 31

Node

Answer 31

A point along a standing wave where the wave has minimal amplitude.

Question 32

Antinode

Answer 32

A point where the amplitude of the standing wave is at a maximum.

Question 33

Standing Wave

Answer 33

A wave that remains in a constant position.

Question 34

Sine Wave

Answer 34

A wave whose form resembles a sine curve.

Question 35

Frequency Spectrum

Answer 35

A representation of the different
frequencies that compose a sound.

Question 36

Infrasound

Answer 36

Sound waves with frequencies below the lower limit of human audibility.

Question 37

Ultrasound

Answer 37

Sound waves with frequencies above the upper limit of human audibility.

Question 38

Sonar

Answer 38

A technique that uses sound propagation to navigate,
communicate with, or detect objects underwater.

Question 39

Acoustical Engineer

Answer 39

A professional who works with sound
and its applications.

Question 40

Phon

Answer 40

A unit of perceived loudness.

Question 41

Sone

Answer 41

A unit of loudness, how loud a sound is perceived.

Question 42

Sound Pressure Level (SPL)

Answer 42

A measure of the pressure
level of a sound, measured in decibels.

Question 43

Doppler Effect:

Answer 43

An increase or decrease in the frequency of sound, light, or other waves as the source and observer move toward or away from each other.