PSY/CS330 Human Factors
5/1/00
Day 1-4
The Physical Stimulus for Audition - 2
uAmplitude is the difference in air pressure between the compression and rarefaction.
lThe measure of sound amplitude is the relative measure called decibel or dB.
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vWhere P = air pressure; P2 = power
ldB SPL, P2=0.0002 dynes/cm2 which is near the absolute threshold for hearing.
NOTE: all amplitude measurements are relative measures - not absolute.  They compare one sound against another.

Do Demo #4 after the section on absolute threshold.

SPL is not always indicated but should be.