Chapter 2: Digital Music
VAB |
VAB TITLE |
Type of VAB |
Description of VAB |
Lab Requirements |
| Download the Ch. 2 VAB lab manual here. | ||||
| 2.1 | Plots of Speech | Explore | Students see their own voice. | Observe. How high can the human voice go in pitch (frequency)? What is your voice's general range? |
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2.2 |
Explore & Annotate |
Sketch Wave allows you to sketch both p(t) and e(t) and hear the resulting sound while it is being created. Try sketching the envelopes and periodic parts of the sounds in Figure 2.12. Can you recreate the sounds of these instruments? |
See Book Section 2.3
Copy and paste the signals to draw and listen to into a Word document OR sketch on graph paper. Describe the qualities of the sound produced. EMAIL table results to Mr. Rummel |
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| 2.3 | Generating Sines and Cosines |
Explore & Annotate |
Students see how a rotating point can plot a cosine and then relate that plot to the sound of the cosine. |
Understand how the unit circle (in radians) can create sinusoids. Be able to draw the position of a dot on a unit circle at 12 positions and translate it into an s(t) sinusoid graph using cos or sine functions. See Web Links for other practice and help pages. |
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2.4 |
Explore & Practice |
Students "measure" a tuning fork by measuring it’s period, an then tuning a cosine to match it. |
A lab skill to acquire. Tuning forks are in the cabinet. Hit only on the heels of your shoes- never on hard objects! Will be on a lab test. | |
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2.5 |
Plotting and Listening to Cosines
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Explore |
Students learn what the Amp, Freq, and Phase of a cosine are, and how they relate to the sound. |
Explore. Pay particular attention to the Chirp block plotting. The actual calculator tables within the lab worksheet don't have to be filled in. We'll use our graphing calculators to explore these functions instead. |
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2.6 |
Explore & Do a Java Applet |
Students are given the FS coefficients for various interesting signals and they adjust the cosine generators to see the signals. This can be frustrating to do on the fly- you need to read the lab instructions! |
The illustration of Fourier Analysis at work. Simple Sine waves add up to make a more complex wave function. See the Phasor Phactory java applet for a way to get quicker values for this technique. Add more harmonics and watch what happens to the approximation. There is a sketchwave component here. You'll need to be able to write the sinusoid series for creating sawtooth, square, and triangle waves and distinguish how they sound. | |
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2.7 |
Explore |
Students generate their own DTMF signals by looking up the frequencies in a table and adjusting their cosine generators. |
Why 2 tones per digit? | |
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2.8a |
Build |
Required Setup |
Must be accomplished first with help from Mr. R | |
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2.8b |
Design & Build |
Build a MIDI player | EMAIL finished worksheet to Mr. Rummel. Solo efforts eligible for bonus credit. | |
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2.9a |
Optional |
Students build the Sketch Wave worksheet in Lab 2.2 from scratch. |
Optional Build. Solo efforts eligible for bonus credit. | |
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2.9b |
Design & Build |
Combines the MIDI Player lab and the Sketch Wave lab. |
Explore. | |
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2.10 |
Explore |
Combines the MIDI Player lab and the Sketch Wave lab. |
Explore. | |
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2.11 |
Explore & Annotate |
Students will see the signals that sound different also look different |
Right Click and "Save Target As" for this Word document. You'll create a match table for the unknown spectrograms and email it to Mr. R |