Short time-span sound echoes which can be created when sound waves bounce between opposite walls in a small or moderately sized room. A shorter version of the ‘slapback’ echo whch can be experienced in a larger hall when sound from a stage is reflected strongly from the rear wall.

A high-speed variation in replay speed causing rapid 'fluttering' pitch variations. See Wow and Flutter or Scrape Flutter

An obsolete computer disk format using a flexible magnetic medium encased in a protective plastic sleeve.

A large capacity solid-state memory configured to work like a conventional hard drive. Used in digital cameras and audio recorders in formats such as SD and CF2 cards, as well as in ‘pen drives’ or ‘USB memory sticks’. Some computers are now available with solid-state flash drives instead of normal internal hard drives.

An effect which combines a modulated delay with the original signal, using feedback to create a dramatic, sweeping sound.

A serial computer interface format based upon the IEEE 1394 standard and named FireWire by Apple (Sony’s i.Link format is also the same interface). FireWire is used for high speed isochronous data transfer, including audio and video. FireWire 400 (IEEE 1394-1995 and IEEE 1394a-2000) or S400 interface transfers data at up to 400Mb/s and can operate over cables up to 4.5metres in length. The standard ‘alpha’ connector is available in four and six-connector versions, the latter able to provide power (up to 25V and 8 watts). The FireWire 800 format (IEEE 1394b-2002) or S800 interface uses a 9-wire ‘beta’ connector and can convey data at up to 800Mb/s.

The ‘turnover’ or ‘corner’ frequency of a high- or low-pass filter. Technically, the frequency at which the signal amplitude has been attenuated by 3dB.

An electronic circuit designed to attenuate a specific range of frequencies. (See low-pass, high-pass and band-pass.) The amount of attenuation depends on the filter slope which is typically either 6, 12, 18 or 24dB/Octave. 

A container for stored digital data that usually has a meaningful name. For example, a Standard MIDI File is a specific type of file designed to allow sequence information to be interchanged between different types of sequencer.

Field Effect Transistor. A solid-state semiconductor device in which the current flowing between source and drain terminals is controlled by the voltage on the gate terminal. The FET is a very high impedance device, which makes it highly suited for use in impedance converter stages in capacitor and electret microphones.