Distortion is the alteration of the original shape (or other characteristic) of something, such as an object, image, sound or waveform.
Dynamic range compression
Dynamic range compression (DRC) or simply compression is a signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds by narrowing or compressing an audio signal's dynamic range.
Effects unit
An effects unit or pedal is an electronic or digital device that alters how a musical instrument or other audio source sounds.
Octave effect
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.
Vocoder
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 (audio effect)
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.
Phaser (effect)
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 (music)
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
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
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.
Wah-wah (music)
Wah-wah (or wa-wa) is an imitative word (or onomatopoeia) for the sound of altering the resonance of musical notes to extend expressiveness, sounding much like a human voice saying the syllable wah.
Talk box
The box has connectors for the connection to the speaker output of an instrument amplifier and a connection to a normal instrument speaker.