ID3 Tag
A means of saving limited descriptive information, including title, artist, album, year of release, genre and comments along with an MP3 track.

indexed file
A file format that permits you to group related audio segments, then access those segments by specifying an index number.

Inharmonic
Containing frequencies that are not integer multiples of the fundamental; > harmonic.

Interface
A linkage between two things. A user interface is the system of controls with which the user controls a device. Two devices are said to be interfaced when their operations are linked electronically. An interface box is often required to convert signals from one form to another. For example, in order to get MIDI data in and out of a computer, you need some type of MIDI interface hardware. This may hook to an existing port on the computer, such as the printer port, or (in the case of the IBM-PC) it may consist of a circuit board that is plugged into one of the computer's internal slots.

I/O
Short for "Input/Output".

ITU
International Telecommunication Union. A group that sets international communications standards. The ITU was previously known as the CCITT.