(1) Before someone nicely types up a solution, I thought I'd just go
    ahead and scan in the solutions of one of our fellow students.  (I
    hope that person doesn't mind :)

http://dsh.cs.washington.edu:8000/Projects/04s126/upload/040326-203520.cgi-lib.16475.1.exam1.pdf

(2) I'm also putting the slides and a bunch of files online at the
    usual place:

    http://dsh.cs.washington.edu:8000/Projects/04s126/precepts/

    I only had time to cover up to the part of adding two waves in our
    meeting today, but the remaining material that I didn't have time
    to cover is also online.

    In the folder labeled as the "other files" column, in addition to
    a bunch of template .java files, I also included two other files:

    In case you're not sure whether your echo filter is producing the
    correct echo effect, pearlharbor_echo.mp3 is a brief 2 minute
    snippet that gives you an idea of what this thing should sound
    like.

    In case you're not sure what the MP3viewer should look like,
    MP3viewer.avi is a small movie that shows what Turtle output we're
    expecting.  If you're having trouble seeing the .avi movie, as
    usual, refer to the instruction at:

    http://dsh.cs.washington.edu:8000/Projects/04s126/precepts/player/

Randy