Music Technology Glossary

**Absorption**

The process by which an object, material or structure takes in sound energy when hit by a

sound wave.

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**ADAT**

Alesis Digital Audio Tape

**ADSR**

Attack, Decay, Sustain, Release: the controls on an envelope generator that are used to shape a sound.

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**Aliasing**

Artefacts created by a

sample rate that is too low.

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**Ambience**

The amount of reverb that sound contains either naturally from a room or artificially added by

an effect.

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**Amplifier**

A piece of equipment used to boost a signal.

**Amplitude**

The height of a waveform; measured from its mean or zero position to its maximum displacement.

**Analogue**

When a signal or equipment uses a continuously

variable physical quantity.

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**Anechoic chamber**

A room designed to completely absorb reflections of sound, minimizing reverb.

**Arpeggiator**

A device that automatically plays the individual

notes of a chord as an arpeggio/broken chord.

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**Arrangement (2)**

1. How the basics of a songs melody, harmony and lyrics are expanded on and ‘fleshed out’ for a musical ensemble or electronics. 
2. Adaptation of an existing composition. reharmonization, melodic paraphrasing, orchestration, or formal development.

**Artefacts**

Unwanted sounds created as a by-product during digital audio processing.

**Attack (dynamics)**

The length of time it takes once the threshold is crossed for the processor to apply its process; for example, when the signal goes above the threshold on a compressor, the attack is the amount of time taken to reduce the signal by the amount specified in the ratio.

**Attack (synthesis)**

The length of time it takes between a note being

started and the point at which it reaches its peak.

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**Attenuation**

A reduction in volume/gain.

**Audio Interface**

A device that connects a computer to audio peripherals such as microphones, speakers and musical instruments.

**Automation**

Programming adjustable parameters to operate automatically during playback and mixing.

**Auto-Tune + Alternatives**

The trade name for a famous piece of software that automatically changes the pitch to the nearest absolute pitch. Can also be used as a creative effect. Alternatives include "Melodyne', 'Flex-Pitch', 'VariAudio'.

**Aux/Bus**

An additional output channel for routing to effects, monitors or as an alternative output. Can be used as a method of grouping channels. Often the same as a bus channel.

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**Balanced**

A connection that has two signals in inversion to one another to reduce noise when put back into

phase.

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**Band pass filter**

A combination of a low pass and a high pass filter that isolates a band around a centre

frequency.

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**Bit depth**

The number of bits used in each sample in analogue to digital conversion.

**Bouncing down**

The process of converting sounds to a new audio file, embedding all processing

applied to them. Normally multiple tracks into fewer tracks but sometimes used to print effects onto an audio track.

**Capacitance**

The ability to store an electrical charge in a capacitor.

**Capsule**

The element of a microphone that responds to the Sound vibrations.

**Capture**

The initial stage of recording in which the sounds are input to the recording device.

**Cardioid**

A microphone polar pattern. Cardioid is roughly heart shaped and picks up sound from the front and side.

**Chorus**

A modulation effect that Simulates multiple instruments or voices performing simultaneously by duplicating an audio signal. This creates a shimmering or "thickening' effect. One copy of the signal is slightly delayed and is also slightly detuned using an LFO. The wet and dry signals are then recombined.

**Clipping**

Overloading a signal so that the top of the waveform becomes squared and causes distortion.

**Coarse-tuning**

The control on a synthesiser or sampler that moves the tuning of a note in semitones.

**Colouration**

The effect that equipment can have on the tonal characteristics of audio through its physical design and manufacture.

**Comb filtering**

The effect created when a slightly delayed version of a signal combines with the direct sound, causing destructive interference

**‘Comping’ (Compiling)**

The process of combining multiple takes of a recording into one master take. Typically used on lead vocals in modern production.

Other notable uses include piecing together varied improvised takes to make up a guitar solo or making a usable part from an inexperienced performer.

**Compression (data)**

The process of encoding a digital audio file to take up less space, but in doing so, often losing some audio information. MP3 files are examples of lossy compressed audio. FLAC files are examples of "lossless' compressed audio, and WAV files are examples of uncompressed audio.

**Compression (dynamics)**

A process for controlling the dynamic range of a sound. it reduces the volume of the peaks of sound above a threshold by a predetermined ratio.

**Condenser microphone**

A microphone that captures sound by measuring the changes in capacitance as the diaphragm moves.

**Convolution reverb**

A reverb that adds ambience by sampling the reflections in a room and calculating the response of sounds within those Spaces.

**Crossfade**

A crossfade creates a smooth transition between audio riles by fading one out whilst the other fades in.

**DAW**

Digital Audio Workstation: a piece of software for recording, editing and mixing audio and MIDI files.

**Decay**

The amount of time that it takes from the peak to drop down to the 'sustain' level.

**Decibels (dB)**

The unit used to measure sound pressure level. This relates to what we perceive as loudness' or volume'. Decibels are measured on a logarithmic Scale.

**De-esser**

The process of removing overly emphasised sibilant sounds including 's\* and 'sh' sounds by applying a dynamics processor to certain frequencies.

**Delay**

The process of delaying a sound electronically and then playing it back after a fixed period of time. Normally blended with the original signal to create an echo effect.   

**Depth (LFO)**

On an LFO, the greater the depth, the wider the range of values for the modulated parameter.

**Destructive editing**

Changes the audio file associated with the sample; processing is not normally reversible. Normally, editing in a DAW __sample editor__ is destructive, although most DAW editing is Non-Destructive. Physically making changes to a tape Is another example of destructive editing.

**Diaphragm**

A small flexible piece of material in a microphone that responds to physical vibrations of sounds. The vibration is then converted into an electrical signal.

**Diffusion**

Scatters sound waves over a large area.

**Digital reverb**

Models a reverb by using lots of delays, which are mathematically calculated. It was first seen in effect units made by Yamaha and Lexicon in the 1980s.

**Distortion**

The normally undesirable sound created when an audio signal overloads and clips, aliasing from poor digital to analogue conversion, or desirable distortion such as overdrive on an electric guitar.

**Dithering**

The introduction of small amounts of unobtrusive randomly generated noise into the analogue to digital conversion process.   

**Dynamic microphone**

A microphone that has a moving coil attached to the diaphragm, within a magnetic field, that generates a small electrical signal.

**Dynamics processing**

The control of dynamics either manually, or with automated devices such as gates and compressors.

**Electromagnetic induction**

The method by which microphones and pickups capture sound and speakers produce it. 

**Envelope generator**

A Synthesiser element that changes a sound's attack, decay, sustain and release over time.

**Equalisation (EQ)**

The balancing of the amplitude of different frequencies within a sound to alter the treble, mid and bass.

**Expander**

A process for controlling the dynamic range of a sound. Expanders increase the dynamic range by making quiet sounds even quieter; they do this by reducing the volume of anything that is below a set threshold level.

**Feedback (delay)**

Part of the delayed signal is fed back into the input of the delay. The greater the feedback, the greater the number of repeats.

**Feedback (live sound)**

The characteristic 'howl' produced when the output from a speaker or monitor signal is picked up by a microphone or guitar pickup, which is in turn sent through the same speaker/monitor, forming an infinite loop.

**Figure-of-eight**

Picks up sound from in front of and behind the capsule. Commonly used in m/s (Mid-Side) recording techniques to give an adjustable stereo image of the sound.

**Fine-tuning**

The control on an electronic instrument that adjusts the smaller increments of tuning between fixed notes. Usually measured in cents (00 cents in a semitone).

**Flanger**

A modulation effect that is created by altering the phase relationship between two signals by modulating a short delay. Flanging creates a distinctive tone caused by comb-filtering. Frequency. The pitch of a sound or the number of wave cycles in a second. Measured in hertz (Hz) or kilohertz (kHz).

**Frequency response**

The accuracy by which a microphone picks up frequencies.

**Fundamental frequency**

Often referred to simply as the fundamental, is defined as the lowest frequency of a waveform. In music, the fundamental is perceived as the the musical pitch of a note.

**Gain level**

The amount of boost applied to the pre-amp stage of an audio channel. Used either to boost signals to an operable level or to boost beyond that point to drive a signal into distortion for musical purposes.

**Gate**

A process for controlling the dynamics of a sound. Gates silence a signal once it drops below a threshold to remove noise. 

**Glide**

Control on a synthesiser used to make one note slide smoothly into another if played one-after another.

**Graphic EQ**

Uses a bank of filters to individually cut and boost specific parts of the frequency spectrum. Commonly used in live sound.

**Hard clipping**

The waveform peaks and troughs are harshly cut-off. Hard clipping sounds harsher than soft clipping, and is exhibited by solid state/transistor amplifiers.

**Harmonic**

A harmonic is part of a wave with a frequency that is a multiple of the fundamental frequency, such as a sine wave. The original signal is also called the 1st harmonic, the other harmonics are known as higher harmonics.

**High pass filter, HPF (aka Low Cut, LC)**

A type of filter that removes only low frequencies below a set point (cutoff frequency) and allows high frequencies through, unaffected.

**Hiss**

additional noise in an audio track caused either by an elevated noise floor or analog source material.

**Hypercardioid**

Picks up sound from in front of the capsule and gives some capture of those behind. Effective at providing partial isolation from other instruments but capturing some of the ambience of the room.

**Jack lead**

A common connector used for audio. Can be used mono, stereo, balanced and unbalanced. Comes in two sizes for different purposes.

**Keyboard tracking**

Spreading a single sample out across the keyboard. The sample is pitch-shifted in response to the key played. Filters in synths also keyboard track so the cutoff frequency moves with the note to ensure all pitches have the same relative harmonic content.

**Leslie speaker**

Contains a rotating horn, with two modes; tremolo (raster) or chorale (slower). Creates a sight shift in pitch and changes in volume and tone as the speaker spins, giving modulation.

**Limiter**

A process for controlling the dynamic range of a sound. It prevents the peaks of sound going above a predetermined threshold.

**Line level**

An audio signal that has a higher level than microphone or instrument level and requires less amplification at the pre-amp stage.

**Low Frequency Oscillator (LFO)**

A control signal used to alter a parameter over time. Commonly used to modulate other elements of the sound.

**Low pass filter, LPF (aka High Cut, HC)**

A type of filter that removes only high frequencies above a set point (cutoff frequency) and allows low frequencies through, unaffected.

**LSB, Least significant bit**

In binary numbers, the least significant bit is the number furthest to the right (i.e. the smallest).

**Mastering**

The final stage of production before music is released.

**Microphone level**

An audio signal that has a lower level than line level and requires more amplification at the pre-amp stage.

**MIDI**

Musical Instrument Digital Interface: a universal language used to communicate between electronic musical instruments.

**MIDI message**

Sent between electronic instruments to communicate information; types of MIDI message include note on/ off, controller, program change and aftertouch.

**Mid-side pair**

A cardioid and a figure- of-8 microphone set up at 90° to one another. Stereo microphone technique that allows for a variable stereo field width.

**Mixing desk**

A device for changing relative levels, EQ and dynamics of a number of audio signals and blending them together.

**Modulation**

Literally means 'changing' but normally used to include effects with some movement to them such as chorus, flanger or an LFO. 

Monitoring

The equipment used to listen to audio during recording or mixing: speakers or headphones.

**Mono**

A single sound source, speaker or channel. Monophonic. A synthesiser that can only play one note at a time.

**MSB, Most significant bit**

In a binary number, the MSB is the furthest to the left (i.e. the largest).

**Multisampling**

Several samples of a single sound source, usually at different pitches and velocities, to increase the realism of a sampled instrument.

**Nodes**

The point on a wave with the minimum displacement.

**Noise**

Unwanted sound.

**Noise floor**

Any piece of analog recording or mixing equipment generates a certain amount of electrical noise that it adds to the audio signal. The term “noise floor” is used to describe this self-generated noise.

**Normalising**

The boosting of audio by the same amount so that the relative volumes remain the same. Commonly used to boost the peak volume to the maximum level before distortion (OdB).

**Nyquist's Theorem**

States that the sample rate of a digital audio system should be at least twice the highest frequency captured.

**Omnidirectional**

A microphone that picks up sound from all around the capsule.

**On/Off Axis**

Placing a microphone at different angles changes the range of frequencies that are captured by the microphone. On-axis capture is brighter and off-axis is duller.

**One-shot sample**

A sample that plays without the end being truncated, no matter how long the key is pressed for.

**OSC, Open Sound Control**

Used to control electronic instruments. It is more modern than MIDI, and is sometimes used in experimental musical controllers.

**Oscillator**

A device found in a synthesiser that generates waveforms used for sound generation and modulation.