Interaction of sound (Edelmen)

Question 1

The decrease in intensity, power, and amplitude as sound travels

Answer 1

attenuation

Question 2

Attenuation is determined by

Answer 2

Path length and frequency

Question 3

More attenuation results in ___ distances and ____ frequencies

Answer 3

longer, higher

Question 4

Processes that contribute to attenuation

Answer 4

reflection, scattering, absorption

Question 5

T/F 10 db of attenuation is negative

Answer 5

TRUE

Question 6

As sound strikes a boundary, a portion of the waves energy may be redirected or

Answer 6

reflected

Question 7

Two forms of reflection

Answer 7

Specular and diffuse

Question 8

When the boundary is smooth, the sound of reflected in only one direction in an organized manner

Answer 8

Specular reflection

Question 9

Wave reflects off an irregular surface, it radiates in more than one direction but back to the transducer

Answer 9

Diffuse reflection (backscatter)

Question 10

Redirection of sound in many directions

Answer 10

Scattering

Question 11

Structures dimensions are much smaller than the beams wavelength

Answer 11

Rayleigh scattering

Question 12

Energy is converted into another energy such as heat

Answer 12

Absorption

Question 13

Number of decibels of attenuation that occurs when sound travels on cm

Answer 13

Attenuation coefficient : db/cm

Question 14

Attenuation lowest to hight from water to air

Answer 14

Water, blood, fat, soft tissue, muscle, bone/lung, air.

Question 15

Distance sound travels in a tissue that reduces the intensity of sound to 1/2 original value

Answer 15

Half-value layer thickness

Question 16

Synonyms of half value layer thickness

Answer 16

Penetration depth, depth of penetration, half-boundary layer.

Question 17

You have a thin half value layer with ___ frequency and ____ attenuation

Answer 17

high

Question 18

Acoustic resistance to sound traveling in a medium

Answer 18

Impedance : rayls

Question 19

Impedance is calculated by

Answer 19

density and speed

Question 20

T/F impedance is calculated not measured

Answer 20

TRUE

Question 21

The incident sound beam strikes the boundary at exactly 90 degrees

Answer 21

Normal incidence

Question 22

Normal incidence synonyms

Answer 22

Perpendicular, orthogonal, right angle, 90 degrees

Question 23

Incident sound beam strikes the boundary at any angle other than 90 degrees

Answer 23

Oblique incidence

Question 24

Sound waves intensity immediately before it strikes a boundary

Answer 24

Incident intensity

Question 25

Intensity of the portion of the incident sound beam that after striking a boundary, it returns back from where it came

Answer 25

Reflected intensity

Question 26

Intensity of the portion of the intensity beam that after striking a boundary, continues forward in the same direction it was traveling

Answer 26

Transmitted intensity

Question 27

Percentage of intensity that passes in a forward direction when a beam strikes an interface between two media

Answer 27

Intensity transmission coefficient ITC

Question 28

Percentage of the intensity that bounces back when a sound beam strikes the boundary between 2 media

Answer 28

Intensity reflection coefficient IRC

Question 29

If the IRC and ITC are added, the result must equal

Answer 29

100%

Question 30

Transmission with a bend is called

Answer 30

refraction

Question 31

With normal incidence, reflection depends on

Answer 31

impedance difference

Question 31

With oblique incidence, the angle of reflection is equal to

Answer 31

angle of incidence

Question 32

What is an oblique incidence with different speeds required

Answer 32

refraction

Question 33

When speed 2 = speed 1, what is the refraction

Answer 33

No refraction

Question 34

When speed 2 is > speed 1 the tranmission angle is ___ than incident

Answer 34

greater than

Question 35

When speed 2 is < speed 1 the transmission angle is ___ than incident angle

Answer 35

less than

Question 36

Impedence is calculated with what 2 things

Answer 36

density x speed

Question 37

To calculate acoustic impedance do

Answer 37

density x prop speed

Question 38

To calculate attenuation do

Answer 38

Min value - max value / 2

Question 39

When a sound strikes a boundary between media at exactly 90 degrees

Answer 39

Orthogonal, perpendicular, right angles, normal

Question 40

A sound strikes a boundary between 2 media at a 60 degree angle. this is ____ incidence

Answer 40

oblique

Question 41

Units for intensity transmission coefficient and intensity reflection coefficient

Answer 41

none

Question 42

Intensity reflection coefficient formula

Answer 42

Reflected intensity / incident intensity

Question 43

Intensity transmitted intensity formula

Answer 43

Transmitted intensity/ incident intensity

Question 44

What is the max permissible value for both the IRC and ITC

Answer 44

1 or 100%

Question 45

What is the min permissible value for the IRC and ITC

Answer 45

0