Here are five real sounds: four are music, one is speech. First, listen to each of them by clicking on the icon:

These sounds range from a simple computer generated scale to a recording of a piano playing Fur Elise. A recording of a male voice is also included. These "real" waveforms are so complicated that plotting them vs. time wouldn't show us much. (You can plot them if you want. See the MATLAB section.)

Spectrum for each signal

Listen to each of the signals again by clicking on the waveform.

Can you point to features in the spectrograms that correspond to the changing tones (or pitch) in the sounds your hear?

Do you see any harmonics? Did you hear any?

Listen very carefully to the sound and try to identify as many features of the spectrogram as possible.

Compare the synthesized notes in Beethoven's Fifth to the real sounds made by the piano in Fur Elise.

Plot the piano signal

Here's a time-domain plot of part of the piano signal.

Does each spectrum change with time? Did the changes make sense? Go to "Chirps" to see if you can predict the spectrum of a signal, or a signal from it's spectrum.