A device for removing or attenuating the noise component of a recording or transmission system without pre-conditioning the signal. Most digital noise-reduction systems are of the Single-ended type.

The waveform of a pure sinusoidal tone which has a waveform defined by a mathematical function derived from a classic periodic oscillation, such as the movement of the tip of swinging pendulum. In a musical context, a sine wave contains only a single fundamental frequency, and  no harmonics.

The ratio of nominal or maximum signal level to the residual noise floor, expressed in decibels and often written as S/N.

The route taken by a signal from the input of a system to the output.

An electrical representation of an audio event.

A part of an audio circuit that splits off a proportion of the main signal to be processed in some way. Compressors use a side-chain process to derive a control signals to adjust the main path attenuation.

A high-frequency whistling or lisping sound that affects vocal recordings, due either to poor mic technique or excessive HF equalisation.

A very low resistance path that allows electrical current to flow. The term is usually used to describe a current path that exists through a fault condition. (See Open Circuit)

a mechanical isolator intended to prevent the transfer of vibrations which may be transmitted through a microphone stand from reaching a microphone where they would otherwise produce unwanted low frequency sound.

A device for recording and replaying MIDI data, usually in a multitrack format, allowing complex compositions to be built up a part at a time.