Sample sources glossary

Wiki Audio - ADSR Envelope

The following glossary defines a variety of music and audio production terminology used in Sample sources.

Glossary
Term	Definition
ADSR	Abbreviation for Attack, Decay, Sustain, and Release. These are the four parameters found on a basic synthesizer or sampler envelope generator. Its function is to modulate some aspect of the instrument’s sound.
Attack	How quickly the sound reaches full volume after the sound is activated (when the key is pressed).
Crescendo	A gradual increase in the volume or intensity of a musical passage.
Decay	How quickly the sound drops to its Sustain level after reaching its initial peak volume level.
Delay (ADSR)	The span of time between a sound's initial keypress and when the sound activates.
Delay (effect)	An echo effect.
DCO	Digitally controlled oscillator (DCO) are used in synthesizers, microcontrollers, and software-defined radios. The name is analogous with "voltage-controlled oscillator." DCOs were designed to overcome the tuning stability limitations of early VCO designs.
Filter/cutoff	A circuit that eliminates certain harmonics from a sound generated by the sound source (the VCO, DCO, etc), and allows the rest of the sound to pass. Using a filter/s to reduce harmonics provides timbre or colour to the sound.
Instrumental	A piece of music without its vocals that is comprised only of instruments. Depeche Mode have produced and released explicitly instrumental music as well as instrumental versions of some songs that normally feature vocals.
Loop	A sample of audio designed to play repeatedly.
Loop point	The "coordinates" that define when a sample of audio is to loop.
MIDI	A protocol that connects a wide variety of electronic musical instruments, computers, and related audio devices for playing, editing and recording music.
Oscillator	A circuit that generates a signal with a frequency in the audible range. This is the core of a synthesizer. A synthesizer can have one (monophonic), two (duophonic) or multiple (polyphonic/paraphonic) oscillators. Every oscillator can have a different waveform with each waveform having a distinct timbre.
Panning	The left/right positioning of a signal within a stereo image.
Release	How quickly a sound fades to silence when a note ends (the key is released).
Resonance	Achieved by applying feedback to a filter: the effect of resonance “boosts” the frequencies around the cutoff frequency. As resonance increases, the feedback increases to a point that the filter can generate a sine-wave tone. This is called “self-oscillation”.
Reverb	A naturally or electronically produced echo-like effect. Reverb is used to add a sense of space to a sound, creating the illusion of distance between the sound and the listener.
Reverse	To flip a sample of audio so that it plays backwards.
Ring modulation	An effect where two waveforms are multiplied together with an output of the sum and difference of the frequencies present in each waveform. The effect is named for the metallic ringing timbre it creates.
Root key	In sampling, the root key of a sample is the key on which a sound plays at its given pitch.
Sequencer	An instrument or interface, either hardware or software-based, that uses control voltages, gate triggers and/or MIDI information to arrange audio events into musical patterns that can be played back programmatically.
Staccato	A musical passage or phrase performed with each note sharply detached or separated from the others.
Sustain	The “constant” volume level the sound is to play at until it is released.
Transient	A high amplitude, short-duration sound at the beginning of a waveform that occurs in phenomena such as musical sounds, noises or speech.
Transpose	To transfer to a different place or context. Musically, this can be to change from one key or note to another, or to play a sample of audio at a higher or lower pitch.
Tremolo	A wavering effect in a musical tone, produced either by rapid reiteration of a note, by rapid repeated slight variation in the volume of a note, or by layering two notes of slightly different pitches to produce prominent overtones.
Truncate	Often seen in samplers and waveform editors. To truncate is to shorten or remove part of a sound.
VCO	Voltage-controlled oscillators (VCO) are electronic oscillators whose oscillation frequency is controlled by a voltage input to generate variable tones in synthesizers. VCOs are used in many synthesizers to aid in the production of electronic music.
Velocity	A data type that responds to the dynamic attack of a key press. This typically controls volume. In practice, a sound will change based on how forcefully a key is pressed. On a piano, pressing a key harder produces a louder, fuller sound. On many synthesizers, velocity can be assigned to modulate any number of settings, including pitch, panning, filters, etc.
Vibrato	A rapid, slight variation in pitch in singing or playing some musical instruments, producing a stronger or richer tone.