MP3s have lots of different numbers, like 32/22 or 64/44. What do they mean?
Way back in the reel-reel days, folks could record audio at 1 7/8, 3 3/4, 7 1/2 or 15 inches per second. The faster speeds gave better fidelity. Today’s MP3 recording does something similar. Two measures of MP3 quality are “bitrate” and “sampling frequency”. Lets take a look at each: Bitrate used to mean the transfer speed of the file. Much OTR is encoded at a bitrate of 32 Kbps (Kilobits per second). That meant that OTR could be sent along a relatively slow internet link at 32 Kbps without breaking up. It also means that the digital OTR file is severely compressed when compared to the original analog file. The lower the bitrate, the smaller the file, and the greater the compression. Since MP3 is a “lossy” compression format, greater compression means lower “fidelity” and more digital artifacts. Since OTR is pretty low-fi to start, and is monaural, 32 Kbps usually worked pretty well. Sampling frequency is the number of times a second the audio is sampled or stored. Audio CDs, for insta
