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Glossary
Amplifier:
A signal processing device that changes the amplitude, and
hence the loudness, of a signal.
Amplitude:
With respect to sound, the peak amount of variation above and
below atmospheric pressure caused by the compression and
rarefaction components of a sound. Amplitude indicates the
amount of energy in a sound and generally correlates with our
perception of “loudness”. The term can also apply to any signal,
hence the term “Amplitude Envelope” which is used to describe
the way a synthesizer’s loudness varies over time when a note
is played.
Chorus:
The creation of the perception of multiple unison voices from a
single voice.
Crossfade:
The process of mixing two audio signals together by increasing
the amplitude of one as the amplitude of the other is decreased.
Effect:
A signal processing device that changes some aspect of the
input signal. An enormous number of different effect types are
available. These include Chorus (which produces a thickening of
the signal), Delay (adding echoes to the signal) and Distortion
(which changes the shape of the waveform usually adding
overtones).
Envelope:
A time-varying signal used to control the development of another
signal after it has been triggered. Envelopes are most often
used for controlling a signal's amplitude. The shape of the
envelope is determined by the number of control parameters.
Usually four parameters are available: Attack Time, Decay Time,
Sustain Level and Release Time.
Filter:
A signal processing device that suppresses or "filters" out
specific parts of a signal's frequency spectrum. Numerous types
of filter are used in audio synthesis. These include Low Pass,
High Pass, Band Pass and Notch. The tone controls on a stereo
amplifier are one example of an audio filter.
LFO:
An LFO or "Low Frequency Oscillator" is a periodic signal
source (usually below audio frequency range) used to modulate
another signal parameter. An LFO can be used for a variety of
effects including vibrato (by modulating the instrument’s pitch)
and tremolo (by modulating the instrument’s amplitude).
Modulation: The variation of one parameter by another. For example, a
signal’s frequency can be “modulated” by an LFO (Low
Frequency Oscillator) in which case vibrato is produced.
LinPlug SaxLab User Guide 2.0.3
