quantification of sound Flashcards
speed of sound
value depends on medium
temperature affects speed of sound
air relatively slow
what determines how fast sound travels
speed of sound is directly proportional to elasticity
inversely proportional to density
measuring sound amplitude
baseline to peak
peak to peak
RMS
RMS
root mean square
measure of the magnitude of varying quantity
useful when the values are positive & negative
peak to peak
useful for sine but not other signals
not possible to differentiate signals w/ same amplitude but different amounts of energy
is power calculated as an average
yes
no negative values
is intensity calculated as an average
yes
no negative values
is pressure calculated as an average
no
RMS
negative values
power
energy transferred per unit done
independent of distance
intensity
amount of sound power passing though a particular point in space
more distance = less intensity
what does 0 dB mean
the measured intensity = reference intensity
what do positive dB mean
the measure intensity is greater than the reference intensity
what do negative dB mean
the measured intensity is less than the reference intensity
are sound intensity & pressure equal
yes
signal to noise ratio
SNR = signal level - noise level
