Glossary
- additive synthesis
- a synthesis technique that is based on the combining of simple waveforms (usually sine waves) at various frequencies, amplitudes and phases to create a more complex waveform. Go to Topic: Sine Waves
- ADSR
- the abbreviation for the classic four-stage envelope; Attack, Decay, Sustain, Release. Go to Topic: Envelope Generators Image Example
- Aftertouch message
- a type of three-byte MIDI command that sends information on a specified channel about how pressure was applied to a key after it was played. Aftertouch may be used as a time-variant controller. Go to Topic: MIDI Data
- aliasing
- false or alias frequencies that arise from a sampling rate that is too slow in the analog to digital conversion process. Go to Topic: Digital Representation
- amplifier
- a modifier module in the synthesis process that controls the amplitude of a signal. Go to Topic: Amplifiers Example
- amplitude
- refers loosely to the strength of the waveform in terms of the amount of fluctuation between the peak positive value or the peak negative value and the zero axis, or to a single instantaneous value at any point of the waveform. The amplitude of a sound contributes greatly to the perceived volume. Go to Topic: Amplitude
- amplitude modulation
- change induced in the amplitude of a signal by means of a control signal from a time-variant controller. Also called AM. Go to Topic: Time-variant Controllers
- analog recording
- a way of documenting the fluctuating voltages of an analog signal over time by imprinting a magnetic record on recording tape whose magnetic imprint is analogous to fluctuations in the voltage that it records. Go to Topic: Sound as a Representation
- analog signal
- an electrical signal that represents sound by containing voltages that fluctuate analogously to the fluctuations contained in the air pressure. Go to Topic: Sound as a Representation
- analog synthesizer
- an instrument that produces analog representations of sound, which the user may design. Presumably these "synthesized" sounds will be subsequently converted to acoustic energy so that we may hear them. Go to Topic: Electronic Music System
- analog to digital converter (A/D converter, also ADC)
- a device which changes an analog signal to a digital representation of sound. This digital representation is a series of numbers that represents the fluctuating voltage of the analog signal. Go to Topic: Sound as a Representation
- attack
- the first stage of an envelope, but may have other meanings depending on context. Go to Topic: Envelope Generators
- attenuate
- to reduce in amplitude. Go to Topic: Low-pass Filters
ADSR - the abbreviation for the classic four-stage envelope; Attack, Decay, Sustain, Release.
