TERMINOLOGY

A B C D E F G H I J K L M N O P Q R S T U V W Q Y Z

A  

ACOUSTICS: The scientific study of sound. 

ABSOLUTE: Existing independently and not in relation to something else. 

AUDIO: Any sound recorded and produced by electronic / digital means. 

A/D [A-D] CONVERTER: Circuit for converting analogue waveforms into a series of equally spaced numerical values represented by binary numbers. The more 'bits' a converter has, the greater the resolution of the sampling process. 

ADSR: Envelope generator with Attack, Sustain, Decay and Release parameters. This is a simple type of envelope generator and was first used on early analogue synthesizers. This form of envelope generator continues to be popular on modern instruments. 

ALGORITHM: A computer program designed to perform a specific task. In the context of effects units, algorithms usually describe a software building block designed to create a specific effect or combination of effects.

AMBIENCE: The result of sound reflections in a confined space being added to the original sound. Ambience may also be created electronically by some digital reverb units. The main difference between ambience and reverberation is that ambience doesn't have the characteristic long delay time of reverberation - the reflections mainly give the sound a sense of space. 

AMP: (Ampere) Unit of electrical current. 

AMPLIFIER: Device that increases the level of an electrical signal. 

AMPLITUDE: Another word for level. Also refers to sound levels or electrical signal levels.

ANALOG: Using a continuous (infinite) range of physical quantities, e.g. weight, length, volume, etc. to represent numbers.

ANALOGUE SYNTHESIS: A system for synthesizing sounds by means of analogue circuitry, usually by filtering simple repeating waveforms. 

ATTENUATE: To make lower in level.

APPLICATION: Alternative term for computer program. 

ATTACK: The time taken for a sound to achieve maximum amplitude. Drums have a fast attack, whereas bowed strings have a slow attack. In compressors and gates, the attack time equates to how quickly the processor changes its gain. 

AUDIO FREQUENCY: Signals in the human audio range: nominally 20 Hz to 20 kHz. 

 B

BANDWIDTH: A means of specifying the range of frequencies passed by an electronic circuit such as an amplifier, mixer or filter. The frequency range is usually measured at the points where the level drops by 3dB relative to the maximum. 

BINARY: Counting system based on only two states - 1s and 0s. 

BIT: Binary digit, which may be either 1 or 0. 

BOOST/CUT CONTROL: A single control which allows the range of frequencies passing through a filter to be either amplified or attenuated. The centre position is usually the 'flat' or 'no effect' position. 

BPM: Beats per Minute. 

BYTE: A piece of digital data comprising eight bits. 

CD-R BURNER: A device capable of recording data onto blank CD-R discs. 

CHANNEL: A single strip of controls in a mixing console relating to either a single input or a pair of main/monitor inputs. 

CHANNEL: In the context of MIDI, Channel refers to one of 16 possible data channel over which MIDI data may be sent. The organisation of data by channels means that up to 16 different MIDI instruments or parts may be addressed using a single cable. 

CHANNEL: In the context of mixing consoles, a channel is a single strip of controls relating to one input. 

CHORD: Three or more different musical notes played at the same time. 

CHORUS: Effect created by doubling a signal and adding delay and pitch modulation. 

CLICK TRACK: Metronome pulse which assists musicians in playing in time. 

CLIPPING: A severe form of distortion which occurs when signal exceeds the maximum level which a piece of equipment can handle. 

COMPRESSOR: Device designed to reduce the dynamic range of audio signals by reducing the level of high signals or by increasing the level of low signals. 

COMPUTER: A device for the storing and processing of digital data. 

CONTINUOUS CONTROLLER: Type of MIDI message used to translate continuous change, such as from a pedal, wheel or breath control device. 

CYCLE: One complete vibration of a sound source or its electrical equivalent. One cycle per second is expressed as 1Hertz (Hz). 

 D

DAMPING: In the context of reverberation, damping refers to the rate at which the reverberant energy is absorbed by the various surfaces in the environment. 

DATA: Information stored and used by a computer. 

DIGITAL: Electronic system which represents data and signals in the form of codes comprising 1s and 0s. 

DIGITAL COMPUTER: A device that calculates, etc. with data represented as a series of 0s and 1s. 

DIGITAL DELAY: Digital processor for generating delay and echo effects. 

DIGITAL RECORDING: A recording in which sounds are represented by a series of digits (0’s and 1’s) indicating the presence or absence of an electronic signal. 

DIGITAL REVERB: Digital processor for simulating reverberation. 

DISC: Used to describe vinyl discs, CDs and Minidisks. 

DOS: Disk Operating System. Part of the operating system of PC and PC compatible computers 

DSP: Digital Signal Processor. A powerful microchip used to process digital signals. 

DRY: A signal that has had no effects added. 

DYNAMICS: Way of describing the relative levels within a piece of music. 

 E

EARLY REFLECTIONS: The first sound reflections from walls, floors and ceilings following a sound created in an acoustically reflective environment. 

EFFECT: Device for treating an audio signal in order to change it in some creative way. Effects often involve the use of delay circuits, and include such treatments as reverb and echo. 

ENVELOPE: The way in which the level of a sound or signal varies over time. 

EQUALISER: Device for selectively cutting or boosting selected parts of the audio spectrum. 

ERASE: To remove recorded material from an analogue tape, or to remove digital data from any form of storage media. 

EVENT: In MIDI terms, an event is a single unit of MIDI data, such as a note being turned on or off, a piece of controller information, a program change, and so on. 

EXPANDER MODULE: Synthesizer with no keyboard, often rack mountable or in some other compact format. 

 F

FADER: Sliding potentiometer control used in mixers and other processors. 

FILE: A meaningful list of data stored in digital form. A Standard MIDI File is a specific type of file designed to allow sequence information to be interchanged between different types of sequencer. 

FILTER: An electronic circuit designed to emphasize or attenuate a specific range of frequencies. 

FLANGING: Modulated delay effect using feedback to create a dramatic, sweeping sound. 

FOLDBACK: System for feeding one or more separate mixes to the performers for use while recording and overdubbing. Also known as a Cue mix. 

FORMANT: Frequency component or resonance of an instrument or voice sound that doesn't change with the pitch of the note being played or sung. For example, the body resonance of an acoustic guitar remains constant, regardless of the note being played. 

FORMAT: Procedure required to ready a computer disk for use. Formatting organises the disk's surface into a series of electronic pigeon holes into which data can be stored. Different computers often use different formatting systems. 

FREQUENCY: Indication of how many cycles of a repetitive waveform occur in 1 second. A waveform which has a repetition cycle of once per second has a frequency of 1Hz (pronounced Hertz). 

FREQUENCY RESPONSE: A measurement of the frequency range that can be handled by a specific piece of electrical equipment or loudspeaker. 

FUNDAMENTAL: Any sound comprises a fundamental or basic frequency plus harmonics and partials at a higher frequency. 

FX: Effects. 

GRAPHIC EQUALISER: An equalizer whereby several narrow segments of the audio spectrum are controlled by individual cur/boost faders. The name comes about because the fader positions provide a graphic representation of the EQ curve. 

HARMONIC: High frequency component of a complex waveform. 

HIGH PASS FILTER (HPF): A filter which attenuates frequencies below its cutoff frequency. 

Hz: Short for Hertz, the unit of frequency. 

I

I/O: The part of a system that handles inputs and outputs, usually in the digital domain. 

J

 JACK: Commonly used audio connector. Can be mono or stereo. 

L

 LFO: Low Frequency Oscillator, often found in synths or effects using modulation. 

LIMITER: Device that controls the gain of a signal so as to prevent it from ever exceeding a preset level. A limiter is essentially a fast acting compressor with an infinite compression ratio. 

LOOP: A piece of music that can be repeated continuously. 

LOW PASS FILTER (LPF): A filter which attenuates frequencies above its cutoff frequency. 

MEG: Abbreviation for 1,000,000. 

MEMORY: Computer's RAM memory used to store programs and data. This data is lost when the computer is switched off and so must be stored to disk or other suitable media. 

MENU: List of choices presented by a computer program or a device with a display window. 

MICROPROCESSOR: Specialised microchip at the heart of a computer. It is here that instructions are read and acted upon. 

MIDI: Musical Instrument Digital Interface. 

MIDI CONTROLLER: A term used to describe the physical interface by means of which the musician plays the MIDI synthesizer or other sound generator. Examples of controllers are keyboards, drum pads, wind synths and so on. 

MIDI FILE (STANDARD): A standard file format for storing song data recorded on a MIDI sequencer in such as way as to allow it to be read by other makes or model of MIDI sequencer. 

MIDI NOTE ON: MIDI message sent when note is played (key pressed). 

MIDI NOTE OFF: Message sent when key is released. 

MIXER: Device for combining two or more audio signals. 

MONITOR: A reference loudspeaker used for mixing. 

MONITOR: The action of listening to a mix or a specific audio signal. 

MONITOR: VDU (screen) display for a computer. 

MOTHERBOARD: The main circuit board within a computer into which all the other components plug or connect. 

MULTITRACK: A recording device capable of recording several 'parallel' parts or tracks which may then be mixed or re-recorded independently. 

NOISE REDUCTION: System for reducing analogue tape noise or for reducing the level of hiss present in a recording.

NORMALISE: A socket is said to be normalised when it is wired such that the original signal path is maintained unless a plug is inserted into the socket. The most common examples of normalised connectors are the insert points on a mixing console.

NYQUIST THEORY: The rule which states that a digital sampling system must have a sample rate at least twice as high as that of the highest frequency being sampled in order to avoid aliasing. Because anti-aliasing filters aren't perfect, the sampling frequency has usually to be made more than twice that of the maximum input frequency.

O

OCTAVE: When a frequency or pitch is transposed up by one octave, its frequency is doubled.

OHM: Unit of electrical resistance.

OPERATING SYSTEM: The basic software that enables a computer to load and run other programs.

OSCILLATOR: Circuit designed to generate a periodic electrical waveform.

OVERLOAD: To exceed the operating capacity of an electronic or electrical circuit.

P

PARAMETER: A variable value that affects some aspect of a device's performance.

PARAMETRIC EQ: An equaliser with separate controls for frequency, bandwidth and cut/boost.

PATCH: Alternative term for Program, referring to a single programmed sound within a synthesizer that can be called up using Program Change commands. MIDI effects units and samplers also have patches.

PEAK: Maximum instantaneous level of a signal.

PHASE: The timing difference between two electrical waveforms expressed in degrees where 360 degrees corresponds to a delay of exactly one cycle.

PHASER: Effect which combines a signal with a phase shifted version of itself to produce creative filtering effects. Most phasers are controlled by means of an LFO.

PEAK: The highest signal level in any section of programme material.

PHANTOM POWER: 48V DC supply for capacitor microphones, transmitted along the signal cores of a balanced mic cable.

PICKUP: The part of a guitar that converts the string vibrations to electrical signals.

PITCH: Musical interpretation of an audio frequency.

PITCH BEND: A special control message specifically designed to produce a change in pitch in response to the movement of a pitch bend wheel or lever. Pitch bend data can be recorded and edited, just like any other MIDI controller data, even though it isn't part of the Controller message group.

PITCH SHIFTER: Device for changing the pitch of an audio signal without changing it's duration.

PORTAMENTO: A gliding effect that allows a sound to change pitch at a gradual rate, rather than abruptly, when a new key is pressed or MIDI note sent.

POST PRODUCTION: Work done to a stereo recording after mixing is complete.

POWER SUPPLY: A unit designed to convert mains electricity to the voltages necessary to power an electronic circuit or device.

POST-FADE: Aux signal taken from after the channel fader so that the aux send level follows any channel fader changes. Normally used for feeding effects devices.

PRE-FADE: Aux signal taken from before the channel fader so that the channel fader has no effect on the aux send level. Normally used for creating Foldback or Cue mixes.

PRESET: Effects unit or synth patch that cannot be altered by the user.

PROCESSOR: Device designed to treat an audio signal by changing its dynamics or frequency content. Examples of processors include compressors, gates and equalisers.

PROTOCOL: A certain “language” by which two electronic devices can communicate.

PUNCH IN: The action of placing an already recorded track into record at the correct time during playback, so that the existing material may be extended or replaced.

PUNCH OUT: The action of switching a tape machine (or other recording device), out of record after executing a punch-in. With most multitrack machines, both punching in and punching out can be accomplished without stopping the tape.

Q

Q: A measure of the resonant properties of a filter. The higher the Q, the more resonant the filter and the narrower the range of frequencies that are allowed to pass. This will be explained in more detail when we talk about filters later in the series.

QUANTIZE: A means of moving notes recorded in a MIDI sequencer so that they line up with user defined subdivisions of a musical bar, for example, 16s. The facility may be used to correct timing errors, but over-quantization can remove the human feel from a performance.

R

RAM: Abbreviation for Random Access Memory. This is a type of memory used by computers for the temporary storage of programs and data, and all data is lost when the power is turned off. For that reason, work needs to be saved to disk if it is not to be lost.

REAL TIME: An audio process that can be carried out as the signal is being recorded or played back. The opposite is off-line, where the signal is processed in non-real time.

RALATIVE: Considered in relation or in proportion to something else.

RELEASE: The time taken for a level or gain to return to normal. Often used to describe the rate at which a synthesized sound reduces in level after a key has been released.

RESISTANCE: Opposition to the flow of electrical current. Measured in Ohms.

RESOLUTION: The accuracy with which an analogue signal is represented by a digitizing system. The more bits are used, the more accurately the amplitude of each sample can be measured, but there are other elements of converter design that also affect accuracy. High conversion accuracy is known as high resolution.

RESONANCE: Same as Q.

REVERB: Acoustic ambience created by multiple reflections in a confined space.

RMS: (Root Mean Square) A method of specifying the behavior of a piece of electrical equipment under continuous sine wave testing conditions.

S

SAMPLE: The process carried out by an A/D converter where the instantaneous amplitude of a signal is measured many times per second (44.1 kHz in the case of CD).

SAMPLE: A digitized sound used as a musical sound source in a sampler or additive synthesizer.

SAMPLE RATE: The number of time an A/D converter samples the incoming waveform each second.

SEQUENCE: A set of events, in which each follows the one before it continuously or in a particular order.

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

SIBILANCE: High frequency whistling or lisping sound that affects vocal recordings, due either to poor mic technique or excessive equalization.

SIGNAL: Electrical representation of input such as sound.

SINE WAVE: The waveform of a pure tone with no harmonics.

SLAVE: A device under the control of a master device.

SOUND WAVE: A vibration made in the air or some other medium by which sound is carried.

SONG FILE: Song data saved to a disk is called song data. Song files are distinguishable by filename; therefore two song files with the same filename cannot be saved on the same location.

STEREO: two-channel system feeding left and right loudspeakers.

SQUARE WAVE: A symmetrical rectangular waveform. Square waves contain a series of odd harmonics.

SAWTOOTH WAVE: So called because it resembles the teeth of a saw, this waveform contains both odd and even harmonics.

SUBTRACTIVE SYNTHESIS: The process of creating a new sound by filtering and shaping a raw, harmonically complex waveform.

SUSTAIN: Part of the ADSR envelope which determines the level to which the sound will settle if a key is held down. Once the key is released, the sound decays at a rate set by the Release parameter. Also refers to a guitar's ability to hold notes which decay very slowly.

SYNTHESIZER: Electronic musical instrument designed to create a wide range of sounds, both imitative and abstract.

SYNCHRONIZATION: To operate, move, turn, etc. at the same time, speed, etc.

T

TIMBRE: The tonal 'colour' of a sound.

TRACK: The term dates back to multitrack tape where the tracks are physical stripes of recorded material, located side by side along the length of the tape.

TRANSPOSE: To shift a musical signal by a fixed number of semitones.

TRIANGLE WAVE: Symmetrical triangular shaped wave containing odd harmonics only, but with a lower harmonic content than the square wave.

TRS JACK: Stereo type jack with Tip, Ring and Sleeve connections.

U

UNISON: To play the same melody using two or more different instruments or voices.

USB: (Universal Serial Buss) A high-speed serial communications protocol which allows (theoretically) up to 127 hot-swappable peripherals to be connected in daisy-chain fashion. USB devices can be unplugged/plugged in without having to reboot your computer. Popular on modern PCs and associated computer peripherals (printers, scanners etc) but also adopted by Apple on their iMac and blue G3 machines onwards.

V

VELOCITY: The rate at which a key is depressed. This may be used to control loudness (to simulate the response of instruments such as pianos) or other parameters on later synthesizers.

VOICE: The capacity of a synthesizer to play a single musical note. An instrument capable of playing 16 simultaneous notes is said to be a 16-voice instrument.

VIBRATO: Pitch modulation using an LFO to modulate a VCO.

VOLTAGES: Electrical force measured in Volts.

VU Meter: Meter designed to interpret signal levels in roughly the same way as the human ear, which responds more closely to the average levels of sounds rather than to the peak levels.

W

WATT: Unit of electrical power.

WARMTH: Subjective term used to describe sound where the bass and low mid frequencies have depth and where the high frequencies are smooth sounding rather than being aggressive or fatiguing. Warm sounding tube equipment may also exhibit some of the aspects of compression.

WAVEFORM: A graphic representation of the way in which a sound wave or electrical wave varies with time.

WHITE NOISE: A random signal with an energy distribution that produces the same amount of noise power per Hz.

WRITE: To save data to a digital storage medium, such as a hard drive.

X

XLR: Type of connector commonly used to carry balanced audio signals including the feeds from microphones.

Y

Z

ZERO CROSSING POINT: The point at which a signal waveform crosses from being positive to negative or vice versa.