Sound Flashcards
(42 cards)
What type of wave is sound?
Sound is a mechanical wave
Sound cannot move through a vacuum; it requires a medium.
Name the seven acoustic parameters.
- Period
- Frequency
- Amplitude
- Power
- Intensity
- Wavelength
- Propagation velocity
What are the variables that compose a sound wave?
- Pressure
- Density
- Distance
What direction do particles move in transverse waves?
Particles move perpendicular to the direction of wave propagation
What do the peaks and troughs of transverse waves represent?
- Peaks: Compression
- Troughs: Rarefaction
What type of wave is sound classified as?
Sound is a longitudinal wave
In longitudinal waves, particles move in the same direction as the wave propagates.
Define in phase waves.
In phase waves occur when peaks and troughs happen at the same time from 2+ waves
Define out of phase waves.
Out of phase waves occur when peaks and troughs happen at separate times between two waves
What type of interference do in phase waves create?
Constructive interference
What type of interference do out of phase waves create?
Destructive interference
What is the source of a sound wave in ultrasound?
The transducer
The tissue acts as the medium.
What is the definition of period in relation to sound waves?
The time from the start of a cycle to the end
In what units is period reported?
Microseconds
Is the period adjustable?
No, it is determined by the sound source
What is the formula for period?
P = 1/F
Define frequency.
Number of cycles per second
In what units is frequency measured?
Megahertz
Is frequency determined by the source?
Yes
What is the formula for frequency?
F = 1/P
What frequency range is classified as infrasound?
Less than 20 Hz
What frequency range is classified as audible sound?
20 Hz up to 20 kHz
What frequency range is classified as ultrasound?
Greater than 20 kHz
What frequency range is used for diagnostic purposes?
2 MHz to 20 MHz
What factors does frequency affect?
- Resolution
- Penetration
