Chapter 2 - Sound Flashcards
The effects of the sound wave upon the biological tissue is called____?
❤️
Biologic effects
❤️
Sound is a type of wave that carries ____ , from place to place.
❤️
ENERGY ❤️
Sound is series of ____ and ____
❤️
Compressions and rarefactions
❤️
Areas of increased pressure and density are called ____?
Compressions
areas of decreased pressure and density are called ____?
Rarefactions
Sound must travel through a _____
Medium
Sound cannot travel through a _____
Vacuum
What type of waves is sound made of???
Mechanical and longitudinal
Sound travels in a _____ line
Straight
_____ ______ IDENTIFY which waves are sound waves
Acoustic variables
When an _____ _____ changes rhythmically in time, a _____ _____ is present.
Acoustic variable
sound wave
What are the 3 acoustic variables?
Pressure ❤️
Density
Distance
____ is this concentration of force within an area,
Force/area❤️
Pressure
Units: pascals (Pa) ❤️
____ is the concentration of mass within a volume
Density
Units: kg/cm^3
_____ measure of particle motion
Distance
Units: cm,feet & miles
What are the two types of waves?
Transverse and longitudinal
_____ ______ : particles move in a perpendicular direction to the direction of the wave
Transverse waves
_____ _____ : particles move in the same direction as the wave
Longitudinal
Regions of higher density and pressure are called ______
Compressions
Regions of lower density and pressure are called _____
Rarefactions
Acoustic _____ inform us of which waves are sound
Variables
Acoustic _____ describe the features of a particular sound wave
Parameters
Name the seven acoustic parameters
Period Frequency Amplitude Power Intensity Wavelength Speed
The time required to complete a SINGLE cycle is called a _____
Or aka as the time from start of a cycle to the start of the next cycle
Period
The typical values for a Period is _____
0.06 to 0.5 ùsecond (less than 1-millionth of a second)
A period is determined by _____
Sound source
Number of CERTAIN EVENTS that occur in a particular time
Frequency
What are the units for frequency?
Per second , 1/sec, Hertz, Hz
Hertz is Just another way of saying per second
What are the typical values for frequency???
2 MHz to 15MHz
Frequency affects ___ and _____
Penetration and axial resolution (image quality)
A wave exceeding 20,000Hz (20 kHz)
Ultrasound
____ this frequency is so HIGH that it cannot be heard by man
Ultrasound
Frequencies between 20Hz and 20,000Hz
Audible sound
Heard by man
Sound with frequencies less than 20Hz
Infrasound
This sound wave cannot be heard by man because it is so LOW
Infrasound
Less than 20Hz