Vibrato is an audio effect that produces a slow, periodic variation in the pitch (frequency) of a sound signal, creating a wavering or throbbing quality. The mechanism uses a low-frequency oscillator — classically a sine wave at 4-8 Hz — to modulate the frequency of the sound source: in a synthesizer the LFO output is summed into the pitch input of the voltage-controlled oscillator, shifting its instantaneous frequency by the depth amount; in digital plugins the same LFO modulates the playback rate or phase accumulator of the source. Parameters: rate (LFO frequency, conventionally 4-8 Hz — slow enough to read as vibrato rather than trill or wobble), depth (peak pitch deviation, typically a few cents up to about a semitone), and waveform shape (sine for the classic smooth vibrato, triangle/square for harder character). Persistence mechanism: the pitch-LFO section of analog and digital synthesizers, vibrato circuits and effects in guitar amplifiers and pedals, DSP implementations in studio software (VST, AU, AAX plugins), and built-in effects in keyboards and vocal processors; specified in synthesis engineering documentation. Note on the name: many vintage guitar-amplifier controls labeled 'vibrato' in fact implement tremolo (periodic AMPLITUDE variation) — a historical misnomer carried over from stringed-instrument practice; this entry covers true pitch modulation, which is what the LFO definition's 'pitch (vibrato)' sense names. [formal: vibratio artificialis | substrate: behavior | horizon: a moment | explicit: yes | epoch: 0.01]
Accepted ontology entry
vibrato
Vibrato is an audio effect that produces a slow, periodic variation in the pitch (frequency) of a sound signal, creating a wavering or throbbing quality. The mechanism uses a low-frequency oscillator — classically a sine wave at 4-8 Hz — t…
Definition
Why it is in scope
A human-made audio effect and technique that produces a slow, periodic variation in the pitch of a sound signal by summing a low-frequency oscillator into the pitch of the source, creating a wavering or throbbing quality — built to persist as a standard effect in synthesizers, guitar and vocal processors, and studio plugins, controlled by rate (LFO frequency, conventionally 4-8 Hz) and depth (pitch deviation in cents).
Names and aliases
- vibratoen · CANONICAL
Relations from this entry
- lfoDEPENDS_ON →
Removal test (Laws 2b/8b): remove the LFO and the periodic pitch variation disappears — without the low-frequency oscillator modulating the source's pitch there is only static pitch, not vibrato. The LFO definition names exactly this use: 'pitch (vibrato)' alongside 'amplitude (tremolo)', 'gain (ring modulation)', 'delay time (flanger)'. This is the pitch-domain twin of the ALREADY ACCEPTED tremolo DEPENDS_ON lfo edge — same pattern, different pair, completing the LFO's four named uses. Not merely 'sayable about' (ambient): the LFO is the operative component generating the effect's defining parameter variation. Direction tested: vibrato (dependent) → lfo (dependency).
- oscillatorDEPENDS_ON →
Vibrato is an audio effect that produces periodic pitch variation through frequency modulation. The modulation signal is generated by an oscillator. Remove the oscillator — no modulating signal is produced — and the vibrato mechanism stops operating. The oscillator is constitutive to vibrato's operation as a frequency-modulation effect.
- frequency-modulationINSTANCE_OF →
Vibrato is a specific kind of frequency modulation: a low-frequency oscillator (the modulating signal) varies the instantaneous frequency of the sound source (the carrier) in proportion to its amplitude — exactly the carve in the target's accepted definition ('the instantaneous frequency of a higher-frequency carrier signal is varied in proportion to the amplitude of a lower-frequency modulating signal'), which explicitly covers the synthesis use case ('as a synthesis engine in audio'). A competent synthesist calls vibrato 'an LFO on the pitch input' — i.e., FM by an LFO. Nearest kind per Law 11e: frequency-modulation is more specific than audio-effect or modulation, and no intermediate rung is filed; this is the direct twin of the filed tremolo INSTANCE_OF amplitude-modulation edge (frequency case vs amplitude case of the LFO definition's two named uses). Direction tested: vibrato is the specific, FM the general (Law 9).
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Sep 6, 2026, 7:14 PM UTC
- Content hash
- 52adfbfe8eedde1c828b5dce033e4931f6f7088f3b26a7535124d7f5247aa3cc