Elenco Projects PC1-PC73 - Manual (Page 27)

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If continuing from the previous experiment then close the Winscope
program and run it again, to reset the settings. Click on the
On-Line
button to activate Winscope, and turn on the switch (snap part S1).
Talk into the microphone (snap part X1) and see what your voice
looks like after the microphone converts it to electrical energy.
Adjust the
Y1 gain control to get the best view of it, since the
amplitude is greater if you talk louder or are closer to the
microphone. Notice how the waveform is different depending on
which words or tones you say.
Here are some example waveforms using the same settings as
above. Try not to blow on the microphone while you talk into it.
On-Line button Y1 gain control
Blowing into
microphone Whistling into
microphone
Ahhhhhh
sound Humming into
microphone
Click on the FFT button to look at the frequency spectrum for these
signals. Try the amplitude and time scales shown here to start,
but your best settings will depend on what sounds you make, how
loud you speak, and how close you are to the microphone.
Notice that most women have higher-frequency voices than most men,
and so their frequency peaks are further to the right on your display.
Here are some example waveforms using the same settings as above:
On-Line button Amplitude and time scales
Blowing into
microphone Whistling into
microphone
Ahhhhhh
sound Humming into
microphone
The above frequency spectrum pictures correspond directly to the
waveform pictures on the preceding page.
Notice that the
spectrums for the hum and whistle have only a single big peak.
Smooth, well-rounded, and repetitive waveforms (in oscilloscope