Hearing and Sound

Question 1

Parts of the Ear (5)

Answer 1

Outer Ear
Ear Canal
Ear Drum
Middle Ear
Cochlea

Question 2

Ear processing sound waves

Answer 2

Converts sounds from waves to mechanical movements then to electrical signals

Question 3

Vibration and sound process (3)

Answer 3

• way to produce sound
• compression pushed molecules together
• rarefaction pulls apart

Question 4

Anatomy of a wave (3)

Answer 4

Frequency
Wavelength
Amplitude

Question 5

Frequency Definition

Answer 5

Number of times a complete cycle occurs per second

Question 6

Wavelength Definition

Answer 6

Physical distance between two points exactly one cycle apart

Question 7

Wave Anatomy Inversely proportional

Answer 7

frequency and wavelength. as one get larger the other gets smaller

Question 8

Maximum Compression location in a waveform

Answer 8

at top of waveform

Question 9

Rarefraction location in a waveform

Answer 9

parts below the reference level

Question 10

Maximum Rarefraction location in a waveform

Answer 10

bottom of waveform

Question 11

Amplitude Def

Answer 11

Magnitude of a signal, intensity of wave

Question 12

Pitch Def

Answer 12

Wavelength (Frequency) determines pitch

Question 13

Frequency Range we can hear

Answer 13

20 Hz to 20,000 Hz

Question 14

Octave def

Answer 14

Interval of tones between a frequency and doubling of that frequency

Question 15

Logarithmic in relation to hearing (2)

Answer 15

The human’s ear’s response to frequency is logarithmic

The way we hear is exponential

Question 16

Bands def (2)

Answer 16

Frequencies can be divided into bands.

Spectrum of hearing is divided into 10 bands where each represents an octave

Question 17

Harmonics def (3)

Answer 17

• sounds are complex waveforms that can be broken down into individual sine waves
• complex waveforms is made up is made up of fundamental frequency plus whole number multiples of that frequency
• whole number multiples are harmonics

Question 18

Complex waveforms def

Answer 18

comprised of a fundamental frequency plus many harmonics

Question 19

Logarithms def

Answer 19

Number of time the number 10 must be multiplied by itself to get a certain value

Question 20

Logarithmic Scale def

Answer 20

Scale with each unit representing a ratio of 10:1

Question 21

Human Perception of Sound (2)

Answer 21

Humans perceive differences in sound levels logarithmically not linearly.
The 10 logarithmic scale is used to measure, record and discuss sound level differences

Question 22

Felhner-Weber Law

Answer 22

The intensity of a sensation is proportional to the logarithm of the intensity of the stimulus

Question 23

Decibels def

Answer 23

Unit of Measurement to describe base 10 or 20 logarithmic relationship of a power ration between two numbers

Question 24

Decibel Equations

Answer 24

We can state the difference in decibels for two powers, voltages or distances

Question 25

Decibel Formula for Power

Answer 25

dB = 10 * log(P1/Pr)

Question 26

Decibel Formula for Voltage

Answer 26

dB = 20 * log(V1/Vr)

Question 27

Decibel Formula for Distance

Answer 27

dB = 20 * log(D1/Dr)

Question 28

Smallest Perceptible change in human hearing

Answer 28

1 dB

Question 29

Just Noticeable Change

Answer 29

3 dB

Question 30

Double the perception of hearing

Answer 30

10 dB

Question 31

Inverse Square Law and Light, Gravity and Electric Field

Answer 31

Every time the distance doubles from the source of energy the energy spreads out and covers 4 times the area. Subsequntly, the energy is 1/4 of what it was previously. *Does not apply to sound: light, gravity and electric field

Question 32

6 dB Per Doubling Rule

Answer 32

Sound pressure is reduced by 6 dB every time the distance is doubled