Chapter 2: Sound and it's Measurement

Question 1

Elasticity of an Object

Answer 1

The springiness of an object
As the distance between molecules decreases, elasticity increases.

Question 2

Brownian Motion

Answer 2

The rapid and random movement of air particles. As heat increases, particle velocity increases.

Question 3

Compression/Condensation Phase

Answer 3

Molecules in the wave close together

Question 4

Rarefaction Phase

Answer 4

Molecules in the wave are pulled apart.

Question 5

Frequency

Answer 5

The number of cycles per second measured in hertz.

Question 6

Period

Answer 6

Time to complete full cycle is known as a period.
Period= 1/frequency

Question 7

As length of a wave increases the frequency

Answer 7

decreases

Question 8

Resonant Frequency

Answer 8

The natural rate of vibration of a mass.

Question 9

Instantaneous Velocity

Answer 9

The velocity of a sound wave at a specific moment

Question 10

Sound Velocity

Answer 10

The speed with which a sound wave travels. As density of an object increases, so does its sound velocity

Question 11

As temperature and humidity increase, sound velocity

Answer 11

increases

Question 12

Wavelength

Answer 12

w= velocity of sound (v)/frequency (f)
Wavelengths decrease as frequency increases

Question 13

Interference

Answer 13

-When more than one tone is introduced, there are interactions among sound waves
-Can result in cancelation or reinforcement of waves

Question 14

Beats

Answer 14

-When two tones of almost identical frequency are presented (e.g., 1000 and 1003 Hertz), there is a noticeable increase and decrease in the resulting sound intensity.
-Changes in amplitude are perceived as beats

Question 15

Fundamental Frequency

Answer 15

The lowest frequency within a complex wave

Question 16

Periodic Sounds

Answer 16

complex sounds that repeat over time

Question 17

Aperiodic Sounds

Answer 17

-vary randomly over time and do not have fundamental frequencies
-aperiodic sounds are perceived as noise

Question 18

Harmonics

Answer 18

-Tones above the fundamental frequency or overtones

Question 19

Formant

Answer 19

Peak of a speech wave

Question 20

Impedance

Answer 20

The opposition a medium offers to the transmission of acoustic energy.

Question 21

Impedance is determined by

Answer 21

resistance and reactance

Question 22

Decibel

Answer 22

The unit of measurement of intensity used in acoustics and in audiometers

Question 23

Audiometric Zero

Answer 23

The lowest sound intensity to stimulate normal hearing 0 dB

Question 24

Sensation Level

Answer 24

The number of decibels of a sound above the threshold of a given individual. Presentation level - Threshold = SL

Question 25

Threshold Level

Answer 25

The lowest level someone can hear at

Question 26

Pitch

Answer 26

a term used to describe the subjective impressions of the “highness” or “lowness” of a sound
Frequency is the physical value

Question 26

Loudness

Answer 26

a subjective experience for intensity
Intensity is the physical value

Question 27

Localization

Answer 27

The ability to tell the direction from which sound comes without seeing the actual source of the sound. Reverberation (echoing) can interfere with this

Question 28

Masking

Answer 28

When two sounds are heard simultaneously, the intensity of one sound may be sufficient to cause the other to be inaudible