3
The Waveform time (ms) pressure • Microphone converts pressure to voltage • Plot pressure vs. time • Sound always has an oscillating pressure vs. time
The Waveform
time (ms)
pres
sure
• Microphone converts pressure to voltage• Plot pressure vs. time• Sound always has an oscillating pressure vs. time
Compare Waveforms
period
T = 2.2 ms
T = 7 ms f = 1/T = 140 Hz
f = 1/T = 460 Hz
pure tone = sine wave
• Definite period single, constant frequency• Described by only two numbers: f, A
ampl
itude
period
How can we describe more complicated sounds?What creates a sine wave?
