Audio effects

Distortion is the alteration of the original shape (or other characteristic) of something, such as an object, image, sound or waveform.

Reverberation, in psychoacoustics and acoustics, is the persistence of sound after a sound is produced.

Octave effect boxes are a type of special effects unit which mix the input signal with a synthesised signal whose musical tone is an octave lower or higher than the original.

A vocoder (/ˈvoʊkoʊdər/, short for voice encoder) is a category of voice codec that analyzes and synthesizes the human voice signal for audio data compression, multiplexing, voice encryption, voice transformation, etc.

Delay is an audio effect which records an input signal to an audio storage medium, and then plays it back after a period of time.

A phaser is an electronic sound processor used to filter a signal by creating a series of peaks and troughs in the frequency spectrum.

Distortion and overdrive are forms of audio signal processing used to alter the sound of amplified electric musical instruments, usually by increasing their gain.

Ring modulation is a signal-processing function in electronics, an implementation of amplitude modulation or frequency mixing, performed by multiplying two signals, where one is typically a sine wave or another simple waveform.

Flanging /ˈflændʒɪŋ/ is an audio effect produced by mixing two identical signals together, one signal delayed by a small and gradually changing period, usually smaller than 20 milliseconds.

Audio feedback (also known as acoustic feedback, simply as feedback, or the Larsen effect) is a special kind of positive feedback which occurs when a sound loop exists between an audio input (for example, a microphone or guitar pickup) and an audio output (for example, a loudspeaker).

Part of the output signal is usually fed back to the input (a 're-circulating delay line'), producing a resonance effect which further enhances the intensity of the peaks and troughs.

Gated reverb is an audio processing technique that is applied to recordings of drums (or live sound reinforcement of drums in a PA system) to make the drums sound powerful and "punchy," while keeping the overall mix clean and transparent-sounding.

A noise gate or gate is an electronic device or software that is used to control the volume of an audio signal.