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Project 1 (Due Sep 12, 11:59pm)

Obtain one or more sounds from freesound.org. (You may also record sounds of your own, including voice.)

  1. [5%] Using a sound between 3 and 5 seconds long, make a 1-second-long cross-fade from the sound to a copy of itself. Make the spliced sound fade in over 1 second and fade out over 2 seconds.

  2. [5%] Using the same sound, make a 20-ms-long cross-fade from the sound to a copy of itself. Make the spliced sound fade in over 20 ms and fade out over 100 ms.

  3. [60%] Use Audacity to manipulate your sounds using splicing, mixing, and any effects you wish. The final mix should have a duration of 30 to 60 seconds. Use the envelope controls in Audacity to shape the loudness contour. E.g. you can fade in and out, ramp up to a climax, or create rhythm with amplitude change. Some form of loudness control should be obvious in your result. Your sound should either be a soundscape --layers of sound with different amplitude, panning, and effects -- or a "beat" -- a rhythmic sequence that loops. In either case, you should construct something original rather than using a ready-made sound.

  4. [30%] Short answers

    A. What was your intention in the design/composition of your sound?

    B. State the duration of your sound from part 3.

    C. Compute the size of the sound file assuming you save the file as .wav with 16-bit samples and a 44kHz sample rate. Does the number match the true size?

    D. Briefly describe the difference between the data in an audio file (like the one you created) and data recorded with MIDI.

    E. In the table-lookup method shown in the Unit 1, (see also Roads pages 90-93), the Frequency box in the diagram holds the Phase Increment, which is added to the phase (i.e. the table index) every sample. Assuming a table size of 1024 samples, a sample rate of 44100 Hz, and a desired fundamental frequency output (the rate at which the table is scanned) of 880 Hz (1 Hz = 1 cycle per second), what value should be used for the Phase Increment?

    F. Suppose you want a table-lookup oscillator that can control frequency within 0.1 Hz. What increment to the "Frequency" (phase increment) in part E would produce a frequency increment of 0.1 Hz?

  5. Submit files as follows in a zip file to Autolab:

    Define the following macros:
    ANDREWID is your andrew ID in lower case;
    FORMAT is one of the two acceptable sound formats {wav, aiff};
    DOCFORMAT is one of the two acceptable document formats {txt, pdf}

    1. ANDREWID_sound0.FORMAT: original sound used in Part 1 and Part 2
    2. ANDREWID_sound1.FORMAT: cross-fade/fade-in/fade-out sound for Part 1
    3. ANDREWID_sound2.FORMAT: cross-fade/fade-in/fade-out sound for Part 2
    4. ANDREWID_origin/: a folder that contains the all the original sound files for Part 3.
    5. ANDREWID_comp.FORMAT: composition for Part 3
    6. ANDREWID_answers.DOCFORMAT: Short Answers for Part 4 (A~F)

    For short answers, please mark clearly which question your answers response to. If you need to provide additional information for your sound (e.g. Part 3), put a textfile (only .txt format is accepted) along with your sound file, with name SOUNDFILENAME_README.txt (SOUNDFILENAME is the sound file name)

    For example, if someone's andrew ID is aabb; AIFF is his/her preferred sound format; and he/she writes answers in .txt format. In addition, he/she want to add some notes for her composition. Then his/her submission should include:
    - aabb_sound0.aiff
    - aabb_sound1.aiff
    - aabb_sound2.aiff
    - aabb_origin/sound.aiff
    - aabb_comp.aiff
    - aabb_comp_README.txt
    - aabb_answers.txt

     

    6. (General submission instructions for Autolab are here, but please follow the specific naming conventions given above on this page rather than following the general directions.)