The flashcards below were created by user
shanamd2010
on FreezingBlue Flashcards.
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definition of sound
vibrations propagated (produced) in an elastic medium
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sound has...
serious emotional content
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sound needs
source of vibration, force, medium, hearing mechanism
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sound is
a disturbance of particles (atmosphere)
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condensation
more molecules = more than atmospheric pressure
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rarefaction
less molecules = less than atmospheric pressure
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simple harmonic motion
- something constantly repeating itself (as in vibration)
- ex) a circle constantly repeats itself
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you can not do anything with sound
until you put numbers to it
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we can talk about sound in relation to
a circle and a sine wave
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synonym of loudness
intensity
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synonym of frequency
pitch
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example of simple harmonic motion
circle
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to make the sound louder
make the circle bigger using diameter and radius
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to make the sound softer
make the circle smaller using diameter and pitch
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to make the pitch higher
rotate the circle faster
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to make the pitch lower
rotate the circle slower
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what represents the rotation of the circle
a sine wave
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sine wave y axis
- Amplitude (volts)
- Amp (v)
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two aspects of sound to model
- loudness (amplitude)
- pitch (period and frequency)
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three sound amplitudes
- Peak Amplitude (Ap)
- Peak to Peak Amplitude (App)
- RMS Amplitude (A rms)
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Ap and App are
instantaneous
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final amplitude is
an average
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finding final amplitude
- S - square all #s
- M - median
- R - take square root
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Arms formula
Arms = .707 x Ap
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pitch can be described by
pitch or frequency
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period
- time of 1 cycle of vibration
- units are seconds or milliseconds
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frequency
- number of cycles per second
- units are Hertz (Hz)
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Heinrich Rudolph Hertz
- German Physicist
- 1857 - 1894
- investigator of electromagnetic waves
- theory behind radio (tv, cell phones, internet, etc)
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period and frequency are related
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in order to do the period and frequency formulas, time must be in
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speed of sound depends upon
the medium
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what determines if the sound will go through an object
wavelength
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low frequencies go through objects because
their wavelengths are longer
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wavelength formula
- ^ = c/f
- ^ = wavelength
- c = speed of sound (ft/sec)
- f = frequency
- units = feet / cycle
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