The point of this assignment is to familiarize yourself with both the Audacity audio editor, and with what complex acoustically-generated sounds are like if you look at and listen to them closely. Audacity is already on all of the computers in the Music Library; you can also download it from http://audacity.sourceforge.net/, and it's well worth having it on your own computer.
Use Audacity to play around with these recorded musical instrument samples from the University of Iowa Musical Instrument Samples collection. As a minimum, open and listen to the oboe F4, oboe A4, and piano A4 files. Zoom in and out on the screen, and select and listen to bits of them, including looping (to do this, just hold down the shift key while clicking play). Then compare the complex real sound to some simple artificial sounds, as follows.
Open a new file and paste about 0.2 sec. of the oboe A4 into it. Then use the first three commands in the Generate menu -- Silence, Tone, and White Noise -- to insert after the oboe excerpt 0.1 sec. of silence; then 0.2 sec. each of sine, square, and sawtooth wave A4's; then 0.2 sec. of white noise. Each pair of sounds should be separated by 0.1 sec. of silence, so the final sound is 1.4 sec. long, with this structure:
[0.2 sec: oboe A4] [0.1 sec: silence] [0.2 sec: sine A4] [0.1 sec: silence] [0.2 sec: square A4] [0.1 sec: silence] [0.2 sec: sawtooth A4] [0.1 sec: silence] [0.2 sec: white noise]Play around with views some more: zoom way in on the waveform till you can see the little oboe cycles, sines, squares, triangles, and, well, noisiness; zoom in even more so you can see the individual samples. Zoom out, and change the vertical axis to dB and spectrum. Instead of the original time-domain view, the spectrum is a frequency-domain interpretation of the sound, showing how strong various frequencies are over time. What do you notice about the spectrum of the oboe note as compared to those of the sine, square, and sawtooth waves? What's distinctive about the spectrum of the white noise vs. all the others? Write a sentence or two or three about each, being as specific as you can. Finally, export the final sound as a .wav, and e-mail it to me (it should be about 120K bytes).