Lab 10

THIS LAB IS DUE ON MONDAY.

The first three of these require test cases.

• Develop the reverse-sound function, that accepts a sound and returns a new sound that is "backward"; that is, reversed in time. You may ignore the right channel of the original sound. You must have test cases for this function.

• Develop the reverse-odd-seconds function, that accepts a sound and returns a new sound that where the odd-numbered seconds are reversed in place, and the even-numbered sounds are untouched. Again, you may ignore the right channel of the original sound. You must have test cases for this function.

• Develop the rescale function, that accepts a sound and a number s and returns a new sound that is stretched or shrunk by s. For instance, if s is 0.5, then the new sound should be half as long as the old one (and have twice the pitch; basically, chipmunk sounds).

• Take seven randomly-chosen seconds, stretch them by a randomly chosen value between 0.5 and 2.0, and play them at randomly chosen overlapping times, with 20 occurring in 30 seconds. Do this problem in the full "#lang racket" language. No test cases are required.