Metric prefix for millionths
micro - µ
Metric prefix for billionths
nano - n
Metric prefix for trillionths
pico - p
Metric prefix for billions
giga - G
Metric prefix for trillions
tera - T
Acceleration due to gravity
32 ft / sec²
Work is a measure of ____.
What is the difference between mass & weight?
Mass doesn't change; weight is a byproduct of gravitational pull
Metric units for mass (M)
kilogram / gram
Metric units for displacement (d)
meter / centimeter
Metric units for velocity (v)
m/s & cm/s
Formula for velocity (v)
v = d/t
Formula for acceleration (a)
a = v/t
Formula for force (F)
F=Ma or =Mv/t
Metric units for force (F)
Newton (N) & dyne
Metric units for Pressure (p)
pascal (Pa) & microbar (µbar)
Formula for work (W)
Metric units for work (W)
Joule & erg
Metric unit for power (P)
Formula for Intensity (I)
Reference value for 0dB as measure of Pressure
Reference value for 0dB as measure of Intensity
10⁻¹² w/m² or 10⁻¹⁶ w/cm²
air molecules forced together
a part in a longitudinal wave where the particles are spread apart
Know in phase & out of phase
duration of a cycle is also known as:
a period =
Hz is a measure of _____ that is measured in ____.
Frequency ... cycles/second
The formula for wavelength is:
speed of sound / frequency = (343m/sec) / (cycles/sec)
A 500 Hz tone has a period(cycle) of _____.
period = 1/freq. = 1/500 = 2msec
the distance between condensating air molecules
Sound level meters measure dB SPL in _____ values.
Root mean squared (RMS)
If 2 sounds are played 180 degrees out of phase, they do what?
cancel each other out
If two sounds are played in phase, the sound is heard ______.
the lowest-frequency component of a complex periodic sound
Humans are hard-wired for _____Hz tones.
a hissing sound that results from a combination of all frequencies of the sound spectrum
More energy at lower frequencies; decreases in amplitude at 3 dB per octave
Similar to Pink Noise with power density decrease of 6 dB per
octave with increasing frequency
noise restricted to the frequency ranges between 10,000 Hz and 22,000 Hz
dB is measured on a _____ scale
dB SPL =
20log (measured sound pressure / reference sound pressure)
If the measured sound pressure is 1,000 times greater than the reference value, what is the dB SPL?
dBSPL = 20log1000 = 60
If the measured sound pressure is 10 times smaller than the reference value, what is the dB SPL?
dBSPL = 20log(1/10) = -20dB
A weighting put less emphasis on _______ frequencies.
SPL greater than ____dB can cause hearing loss.
As the volume of the air cavity in a tube gets larger, the frequency gets ______.
inverse square law
as distance increases from the sound source, intensity decreases
collects dB levels over time
permissible exposure limit (PEL) is set by ______.
OSHA (U.S. dept of labor)
The NIOSH recommendation is set by the _____ and is stricter than OSHA.
double or half of adjacent frequency (e.g. 125, 250, 500, 1000, 2000 etc..)