Sound waves

Question 1

Sound

Answer 1

Experential or physical

Question 2

Experential sound

Answer 2

What we hear with our human auditory system

Question 3

Physical sound

Answer 3

What travels from the source of the sound of the listener

Question 4

Infrasound

Answer 4

Sound waves of less than 20Hz

Question 5

Audible sound

Answer 5

Frequency between 20Hz and 20kHz

Question 6

Ultrasound

Answer 6

Sound waves greater than 20kHz

Question 7

Use of ultrasound

Answer 7

Diagnostic sonography uses ultrasound to produce images of anatomy, motion and flow

Question 8

Transducer

Answer 8

Source of the sound waves

Question 9

Tissue

Answer 9

Medium through which the sound travels

Question 10

Sound

Answer 10

A traveling variation in pressure, when the speaker speaks variation in pressure are produced in the throat and mouth. These pressure variation travel through the air to the listener where they stimulate the auditory response in the ear and brain.

Question 11

The acoustic variables

Answer 11

Pressure
Density
Distance

Question 12

It is a sound wave when…

Answer 12

One of these acoustic variables have rhythmic oscillations

Question 13

Wave

Answer 13

A traveling variation in one or more quantities called variables.

Question 14

Pressure

Answer 14

Variation in soun waves cause the particles of the medium to vibrate back and forth
Acoustic variables becuase of quantities vary in sound wave

Question 15

Density

Answer 15

The concentration of matter. Acoustic variables because of quantities that vary sound waves.

Question 16

Rarefraction

Answer 16

Regions of low pressure and density

Question 17

Compression

Answer 17

Regionscof high pressure and density

Question 18

Longitudinal wave

Answer 18

A mechanical, compressional wave in which back and forth particle motion is parallel to the direction of the wave eg. sound wave

Question 19

Transverse waves

Answer 19

Particles move in a direction perpendicular to the direction of that the wave propagates. Involves no particular motion.

Question 20

Sound wave characteristics

Answer 20

1. The molecules in the medium vibrate back and forth in a fixed position.
2. cannot travel through a vacuum
3. Sound molecules are compressed and rarefied
4. travels in a straight line
5. longitudinal

Question 21

In phase

Answer 21

Pair of waves when their peaks occur at the same time and the troughs, at the same location

Question 22

Out phase

Answer 22

Pair waves when their peaks and troughs occur at different times

Question 23

Interference

Answer 23

The waves lose their individual characteristics at that moment and combine to form a single wave.

Question 24

Constructive interference

Answer 24

Pair of in phase waves results in the formation of a single wave or greater amplitudes than either of its components

Question 25

Deconstructive interference

Answer 25

Pair out of phase waves results in the formation of a single wave of lesser amplitude than either of its components

Question 26

Sound wave parameters

Answer 26

1. Period 2. Frequency 3. Amplitude 4. Power 5. Intensity 6. Wavelength 7. Speed

Question 27

Period

Answer 27

The time it takes to generate a single wave cycle Determined by the sound source, not adjustable

Question 28

Frequency

Answer 28

The number of wave cycles that occur in a second. Has an impact on resolutions and penetration images. Not controlled by medium. Not adjustable.

Question 29

Bigness parameters

Answer 29

Parameters that describe the size, magnitude of the wave. Amplitude, power, intensity

Question 30

Amplitude

Answer 30

Size/magnitude/ straight of the wave. Difference between the max value and the average of an acoustic variable. Determined by the source and adjustable

Question 31

Power

Answer 31

The rate of energy transfer, describes the bigness of the wave. Decreases as the sound propagates depending on the characteristics of the medium. Is adjustable.

Question 32

Intensity

Answer 32

The concentration of energy in the sound beam. How the power I spread or distributed in space. Depends on the power of the beam and the area over which the power is applied.

Question 33

Wavelength

Answer 33

The distance of one complete cycle. Shorter wavelength = higher quality image = high frequency transducer

Question 34

Propagation of speed

Answer 34

The distance that a sound wave travels through a medium in 1 sec.

Question 35

Stiffness

Answer 35

The ability of an object to resist compression

Question 36

Density

Answer 36

The relative weight of an material

Question 37

Speed and medium characteristics

Answer 37

If two media are equally stiff, the denser medium will, have a lower speed