Week 5

1 - Bush SotU 1, RM at 500Hz
2 - Bush SotU 2, RM, rising cycle 0 to 1000Hz
(and for comparison, the Gold Cylon leader)

3 - Unprocessed Lark Sparrow
4 - Lark Sparrow with 1kHz AM
5 - Lark Sparrow with 1kHz RM

6 - signal of 1kHz, mod freq of 5, changing modulation depth from 0 to 20000 - note the fluttering helicopter sound
7 - mod freq: 14,061, mod depth: 2,656, carrier from 0 to 20,000 - note the musical scale that appears
8 - R2D2 upchucking the above use phasor, this uses cycle
9 - 'Wow' created with modrate of 1 mod depth of 199 on freq of 128

White noise, pink noise, red noise, and brown noise

A history of digital audio compression

A good (well, pretty good) explanation of MP3

And a slightly less technial explanation of MPEG, psychoacoustics, etc. is here

MPEG is lossy, just like JPEG, but bitrates of 48 or 56 produce files with no audible artifacts (at least on my speakers) and going this far below the typical 128kbps means an additional compression of maybe 4:1. The artifacts produced by too much compression always sound 'watery' to me, and, not coincidentally I imagine, seem to be an exact synesthetic representation of JPEG compression artifacts. JPEG artifacts typically occur at edges between areas of different colors, and MPEG artifacts seem to happen more when there are the audio equivalent of that, having many high- and low-frequencies occuring together. But, just as texture in a JPEG image can mask the effects of artifacts, rich aural texture can mask MPEG artifacts.

A neurobiology and behavior student has made hamster-controlled midi music (mirror)
As usual, Markov chains were involved