Term
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Definition
| 2 items that are not associated. |
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Term
| Directly Related/Directly Proportional: |
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Definition
| 2 items that are associated such that when 1 item increases, so does the other item. |
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Term
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Definition
2 items that are associated or affiliated.
(The relationship between the items does not have to be specified.) |
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Term
| Inversely Related/Inversely Proportional: |
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Definition
| 2 items are associated such that when 1 item increases, the other item decreases. |
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Term
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Definition
| A special form of inverse relationship where when 1 item increases, the other decreases and when both are multiplied together they = 1. |
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Term
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Definition
Biologic tissue.
What sound travels through in the body. |
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Term
| Sound Wave/Acoustic Wave: |
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Definition
| A mechanical, longitudinal wave that travels in a straight line. |
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Term
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Definition
| Sound molecules that are squeezed together. |
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Term
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Definition
| Sound molecules that are stretched apart. |
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Term
| Acoustic Propagation Properties: |
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Definition
| The effects of the medium upon the sound wave. |
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Term
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Definition
| The effects of the sound wave on biologic tissue (media) through which it passes. |
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Term
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Definition
| Properties in a medium that change when sound goes through it. |
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Term
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Definition
| Concentration of force in an area. |
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Term
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Definition
| Concentration of mass in a volume. |
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Term
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Definition
| Measure of particle motion, |
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Term
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Definition
| Must have 1 of 4 acoustic variables in rhythmic oscillation. |
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Term
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Definition
| Describe the features of a particular sound wave. |
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Term
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Definition
| The time from the start of one cycle to the start of the next cycle. |
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Term
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Definition
| The # of cycles that occur in 1 second. |
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Term
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Definition
The difference between the average (mean) value & the maximum value.
The "bigness" of a wave. |
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Term
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Definition
| The difference between maximum & minimum values of an acoustic variable. |
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Term
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Definition
The rate that work is performed.
The rate of energy transfer. |
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Term
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Definition
| The concentration of energy in a sound beam. |
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Term
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Definition
| The length (distance) of a single cycle. |
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Term
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Definition
| The rate that sound travels through a medium. |
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Term
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Definition
Particles move in a perpendicular direction (right angle) to the direction of the wave.
Particles move up & down. Wave moves left to right. |
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Term
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Definition
Particles move in the same direction as the wave.
Front to back. Parallel.
Sound is this kind of wave. |
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Term
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Definition
When a pair of waves' peaks & troughs occur at the same time & place.
Amplitude is stronger. |
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Term
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Definition
When 2 waves' peaks & troughs occur at different times.
Amplitude is weaker. |
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Term
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Definition
| When multiple sound beams arrive at the same place & time and combine to form a single wave. |
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Term
| Constructive Interference: |
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Definition
| 2 in-phase waves that combine to make one big wave. |
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Term
| Destructive Interference: |
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Definition
| 2 out-of-phase waves that combine and make one small wave. |
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Term
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Definition
The size or strength of a sound wave.
(The 3 "bigness" parameters.) |
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Term
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Definition
Sound too low for human hearing.
F < 20Hz |
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Term
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Definition
Within range of human hearing.
F = 20Hz-20KHz |
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Term
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Definition
Frequencies above human hearing.
F > 20KHz |
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Term
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Definition
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Term
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Definition
The ability of an object to resist compression.
Material will retain its shape. |
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Term
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Definition
The rate of energy transfer.
Thera |
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Term
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Definition
The relative weight of a material.
(Also see compressibility & elasticity) |
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Term
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Definition
| A collection of cycles that travel together. |
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Term
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Definition
The actual time from the start of a pulse to the end of that pulse.
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Term
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Definition
| The distance that a pulse occupies in space from the start to the end of a pulse. |
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Term
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Definition
The time from the start of 1 pulse to the start of the next pulse.
Includes 1 PD + 1 listening time. |
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Term
| Pulse Repetition Frequency: |
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Definition
| The # of pulses transmited into the body each second. |
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Term
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Definition
| The % (fraction of time) that the system transmits a pulse. |
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Term
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Definition
The rate at which energy passes through unit area.
The beam's power divided by its area.2 |
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Term
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Definition
A method of rating numbers.
A log of numbers that represent the # of 10s that are multiplied to create the original number. |
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Term
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Definition
A unit for measuring signal strength & brightness of images.
(Total Attenuation) |
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Term
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Definition
| The weakening of a sound waves intensity, power, & amplitude as it travels through a medium. |
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Term
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Definition
A redirected portion of a wave's energy that goes back to the sound source after striking a boundry.
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Term
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Definition
A smooth boundary reflecting in only 1 direction.
(Angle of incidence = Angle of reflection) |
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Term
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Definition
| An irregular surface causing reflection in more than one direction. |
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Term
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Definition
| The random redirection of sound. |
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Term
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Definition
Structure's dimensions are much smaller than the beam's wavelength.
Redirects the sound wave equally in all directions. |
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Term
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Definition
| When U.S. energy is converted into another form of energy, such as heat. |
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Term
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Definition
| The # of decibels of attenuation that occur when sound travels 1 cm. |
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Term
Half-Value Layer Thickness:
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Definition
| The distance sound travels in a tissue that reduces the intensity of sound to 1/2 its original value. |
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Term
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Definition
| The acoustic resistance to sound traveling in a medium. |
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Term
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Definition
The sound wave emitted from the source (transducer).
Fo |
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Term
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Definition
| The incident sound beam strikes the boundary at exactly 900. |
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Term
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Definition
| The incident sound beam strikes the boundary at any angle other than 900. |
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Term
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Definition
| The intensity of a sound wave right before it strikes a boundary. |
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Term
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Definition
| The intensity of the returning portion of the sound beam after it strikes a boundary. |
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Term
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Definition
| The intensity of the portion of the sound beam that continues forward after striking a boundary. |
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Term
| Intensity Reflection Coefficient: |
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Definition
| The % of the intensity that bounces back when a sound beam strikes the boundary between 2 media. |
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Term
| Intensity Transmission Coefficient: |
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Definition
| The % of intensity that passes in the forward direction when the beam strikes a boundary between 2 media. |
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Term
| The Law of Conservation of Energy: |
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Definition
| The sum of the % of sound reflected and the % of sound transmitted must equal 100%. |
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Term
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Definition
| The angle between the incident beam and an imaginary line that is perpendicular to the boundary. |
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Term
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Definition
| The angle between the reflected beam and the line perpendicular to the boundary. |
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Term
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Definition
A change in direction of wave propagation when traveling from 1 medium to another.
"Transmission with a bend." |
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