The Pasco Fourier synthesizer produces two 440 Hz fundamentals and eight exact harmonics. You can vary the amplitude and phase of any of these signals and add them up to generate a complex wave form. The output goes to an oscilloscope and also to a speaker so the class can hear the wave form. The two fundamentals can be added alone to show the sum of two sine waves, or sent to two speakers to demonstrate acoustical interference.
The Fourier analyzer shows the power spectrum of a complex wave form on an oscilloscope.
Applet by Fu-Kwun Hwang --- Virtual Physics Library [1]
How to play:
The default value for base frequency is f=100Hz, you can change it from the TextField (20 < f < 2000). The ear is 1000 times more sensitive at 1kHz than at 100Hz.
frequency range | ||
speech | song | |
adult male | 80-240 | up to 700 |
adult female | 140-500 | up to 1100 |
Links:
[1] http://www.physics.ucla.edu/demoweb/ntnujava/indexPopup.html