Glossary – L
Layering – Refers to almost any blending of similar multiple musical parts or sounds at once, often combined on one channel or assigned to one controller. In audio recording, layering usually involves recording similar takes of the same instrument or vocal (or duplicating parts with slight delays or chorusing effects) to create a fuller, richer sound than the vocal/instrument by itself. In sound design, it also refers to blending multiple samples (example: two or more drum sounds) to create a fuller sound.
Lead – The musical instrument that plays the melody, including the vocal.
Lead Sheet – A shorthand form of music notation (similar to a chord chart) that displays the basic essential elements of a song so musicians can follow along without the full notation of every note or expression. Lead sheets most commonly include a melody line written in music notation with chord changes above the staff, and lyrics below it. (See also “Chord Chart.”)
Leakage – Sounds from other instruments and sound sources that were not intended to be picked up by the microphone.
Level – The amount of signal strength; the amplitude, especially the average amplitude.
Limiter – A type of compressor that sharply reduces (limits) the gain of the signal when the audio level reaches a certain threshold, typically used to prevent overload and signal peaking. A compressor effectively becomes a limiter when its ratio is 10:1 or higher. (See also “Compressor.”)
Line Input (“Line In”) – An input designed to take a line level signal.
Line Level – The standard audio signal level that runs through interconnecting cables in the studio or sound system, before the signal is amplified and sent to the speakers. Line level is often described in comparison to mic level or instrument level (which usually require preamplification to bring them up to line level).
Line Output (“Line Out”) – Any output that sends out a line level signal, such as the output of a console that feeds a recorder.
Live – 1) A term describing a space with a reverberant or reflected sound. In a “live” space, the sound waves are active or “live.” 2) Occurring in real time, as opposed to previously recorded.
Live Room – The large, main room of the recording studio where most of the instruments and/or vocalists perform. So called, not just because there is room for live performances, but because the room has been acoustically treated to produce a pleasing amount of live reverberation.
Live Recording – A recording session where all the musicians are playing at once with no overdubbing.
Lo-Z – See “Low Impedance.”
Local On/Off – A MIDI message that controls the internal sound module of a synthesizer or MIDI controller. “Local On” triggers the internal module when the keyboard is played; “Local Off” disconnects it. “Local Off” is frequently used to prevent unwanted looping of MIDI messages in some configurations, or when controlling the internal module via another controller.
Loop – 1) Effectively, any piece of music or data that repeats endlessly. Before digital audio and sampling, loops were created by looping tape. Today, loops are used in samples to sustain a sampled note for as long as the note is triggered, while drum loops and other music loops are common in modern music production. 2) Another term for antinode, or the points of maximum displacement of motion in a vibrating stretched string or a sound wave. (See also “Standing Wave.”)
Loudness – A term referring to how the human ear perceives incoming sound waves. This term seems self-explanatory, but it’s deceptive. We commonly think of loudness as it relates to the volume of a sound, but this is an indirect relationship. In acoustic terms, volume is more about the amplitude of the sound waves, while loudness describes how our ears hear the intensity of those waves.
Low-Frequency Oscillator (LFO) – A circuit that emits low-frequency electronic waveforms below the audible level of human hearing (20 Hz or less). This low-frequency waveform creates a rhythmic pulse that is used to modulate various parameters in the audio signal, such as pitch or volume. LFOs are frequently used in samplers, synthesizers and signal processors to create such effects as vibrato, tremolo, and phasing.
Low Impedance – (abbreviated Lo-Z) Described as impedance of 500 ohms or less. (See also “Impedance.”)
Low-Pass Filter – An audio filter or device that attenuates signals above a certain frequency (the cut-off frequency) and passes signals with frequencies that are lower than the cut-off.
Lows or Low-End – Short for “low frequencies,” loosely referring to bass-frequency signals below 250 Hz. Usually meant in the context of “highs, mids and lows” in an audio signal.