Файл: Sound Tech Terms Dictionary.pdf

K

k:  Kilo.  One Thousand.  For example, 20kHz=20,000Hz.

K:  (1) Often used in place of “k” for one thousand, but precisely means 1,024 bytes, or   2

10

bytes, abbreviated KB.  (2) Temperature measured by the Kelvin scale.  The various film and
TV lighting sources are always measured by the Kelvin scale, and most color film stocks are
balanced to give proper color reproduction at either 3,200˚K (tungsten-halogen lamps) or
5,400˚K (noonday sun).

key:  In music, the key is the pitch of the tonic of the musical scale used.  Tonal music gravi-

tates toward a home key, the tonic.  Key is established by the use of a fixed scale of notes
based on this tonic note and can be emphasized by other, related notes and by cadences.  The
tonic note or chord assumes greater importance than the others and leads, by extension, to a
hierarchy of chords with the dominant (based on the fifth note of the scale) of particular sig-
nificance.  See temperament.

keyboard control voltage:  The control voltage parameter that tells the signal-generating cir-

cuit exactly which key has been depressed.

keyboard rate scaling:  See envelope tracking.

keyboard scaling:  A function with which sound can be altered smoothly across the range of

the keyboard by using key number as a modulation source.  Level scaling changes the loud-
ness of the sound, while filter scaling changes its brightness.

key code:  See keyboard control voltage.

key follow:  See envelope tracking.

keying input:  In a signal processing or generating device, an input for a control signal that

determines the type and amount of processing applied to the audio signal, or of the sound
produced, respectively.

keying signal:  The signal sent to the keying input of a signal-producing or signal processing

device, which then activates the device.

key map:  A keymap assigns a sample to each MIDI note or key on a keyboard.  The map is set

to respond to a specific MIDI channel so incoming MIDI notes on that channel trigger the
samples assigned to them.

key numbers:  Numbers on the side of film stock created during film manufacture that are

visible on the developed negative and positive prints made therefrom.

key pressure:  See poly pressure.

key signature:  The group of sharp or flat symbols placed immediately after the clef symbol on

the stave at the beginning of a piece of music, and at the beginning of every subsequent stave,
to indicate the key.  These sharps or flats are presumed to be active for the duration of the
piece or section, unless cancelled either temporarily (for one bar or part of the current bar) by
an accidental, or more permanently, by the placing of a new key signature.

keyboard tracking:  See envelope tracking.

K

kirsch:  In film, means when a director has requested a change in the sound and then gives

his or her approval to what was, in fact, no net change, either deliberately or accidentally on
the part of the mixers.  Kirches can be self-inflicted as when a mixer adjusts a control when it
is not in the signal path, or listens for a change while the PEC/direct paddles are in playback
mode, as opposed to input mode.

KSHRFOO:  The traditional first seven microphone input channels on a mixing console in a

rock recording/SR set-up.  By convention, these are for the Kick-drum, Snare, Hi-hat, Rim,
Overhead left, and Overhead right mics on the drum kit.

L

L/A synthesis:  Linear Arithmetic synthesis.  A sound synthesis method developed by Roland

that creates new sounds by attaching the attack portion of a sampled waveform to a simpler
waveform.  Human sound recognition is heavily influenced by hearing the attack transient
part of a sound, but simple waveforms require less storage than samples.  By combining the
two, L/A synthesis is capable of relatively sophisticated sounds with modest data storage re-
quirements.

labels:  Special non-audio information encoded along with the audio in digital recording sys-

tems, used to encode information about the recording session, number of microphones used,
dates, etc.

lacquer master:  The disc produced from a master recording tape which is used to press vinyl

copies.

land:  (1) The flat area of vinyl between the grooves of a record.  (2) The flat area between the

laser-carved pits of a CD.

largo:  Italian for “broad.”  A slow or stately tempo, 48-60 bpm.

later reflections:  See early reflections.

Lavalier microphone:  A small microphone, either condenser or dynamic, which can be easily

hidden in a piece of clothing so as not to be seen by the camera.  Also called a peanut.

layback:  Transfer of the finished audio mix back onto the video edit master.  See layoff.

layback recorder:  A videotape recorder, usually 1” format, on which a mixed soundtrack

with all DME stems can be re-recorded in sync with the edited video master.  Because of its
special purpose, a layback machine should have less flutter and higher quality audio heads
and electronics than standard 1” video decks.  Some layback machines designed especially
for that purpose have no video reproduction capability at all.  They merely read timecode
and do an extremely high-quality job of recording audio, and nothing else.  The layback
process is also called re-laying.  See layback, layoff.

layer:  See split point.

layering:  Sounding two or more voices, each of which typically has its own timbre, from each

key depression.  Layering can be accomplished within a single synthesizer, or by linking two
synths together via MIDI and assigning both to the same MIDI channel.

layoff:  Transfer of audio and timecode from the video edit master to an audio tape.  See lay-

back.

layover/layup:  Transfer of audio onto hard disk or multitrack tape.

LBR:  Laser Beam Recorder.  The device used to create a CD master for duplication.

LC Concept:  A system, developed by a French company of the same name, for implementing

digital audio for cinemas.  The system relies on the presence of an optical timecode on the
film which is used to synchronize the digital audio soundtrack stored on a separate magneto-
optical disc reader, i.e., the film carries no sound at all, allowing for multilingual presentation
from the same film print.  This also solves the problem of getting high-quality audio onto
film.

L

LCRC:  See LCRS.

LCRS:  Left, Center, Right, Surround.  The four playback channels used in 35mm motion pic-

tures, now available on home hi-fi systems.  L, C, and R speakers are located behind the
screen.  The S channel surrounds the audience and may be mono or encoded stereo.  See ma-
trix, surround-sound.  Variants include LCRC, when the fourth track is to be assigned to the
center, or even CCCC, as in a center-channel dialog premix.

lead sheet:  An abbreviated musical score, consisting of a melody line with chord names or

symbols, and sometimes including lyrics.

leader:  Blank (unexposed) motion picture film attached to the beginning or end of a reel of

film, usually used for threading a playback machine, and which contains information about
the reel’s content such as film title, reel number, etc. as well as the count-down section.
Opaque leader is used in A and B Rolls, in editing workprints and film soundtracks, to fill spaces
between specific sound effects or musical segments, or to fill in for picture or sound segments
to be added later.  See also Academy leader, SMPTE Universal leader, plastic leader, fill leader.

leadering:  The process of removing the out-takes, count-offs, and noises between takes in a

magnetic tape (and by extension, digital) recording.  In analog magnetic tape recording, this
process also involves inserting leader tape between songs.

leader tape:  Nonmagnetic plastic or special paper tape that is spliced onto magnetic tape be-

tween musical selections and at the beginning and end of the magnetic tape, protecting the
tape and delimiting the selections.  Some leader is timed and has marks every 7  

1

2

” or 15” to

allow the tape editor to insert the desired time between selections.

lead-in:  See spiral.

leakage:  The pick-up of unwanted, off-axis sounds by a directional microphone due to the fact

that its directional pattern is not ideal or that the microphones and/or instruments are not
sufficiently isolated from one another, as in a multitrack studio recording.  Also called spill.

learning curve:  In mechanical or electronic systems controlled by computers, the computer’s

ability to learn the hardware/software, input/output environment and use this information
to control the system’s state.

LEDE:  Live End Dead End.  A commercial trademark used to indicate a particular acoustical

design of a recording studio control room.  In this design, the area around the monitors is
made acoustically absorbent, or dead, while the area behind the listener’s position is made re-
flective, or live, in an attempt to increase the accuracy of the reproduction.  See also ESS, RFZ.

LFE:  Low-Frequency Effects.  The equivalent of the subwoofer designation for audio-for-

video, where the low-frequency band between about 20Hz-120Hz is matrixed or channeled
for replay.  In home audio systems, the subwoofer will frequently contain LF information
from the main channels in addition to the original LFE track.  See also in-band gain.

legato:  A musical effect whereby the decay of one note overlaps the attack of the next.

leger line:  See stave.

L

Lemo:  A Swiss company which makes high-quality, very dense connectors.  Rarely used,

Lemo connectors are found on some specialty audio equipment, such as Soundfield micro-
phones (because of the large number of capsules) or compact mics which require a high den-
sity of pins in a small space.  There is no standard for the pin-outs in Lemo connectors, a fact
which contributes to their scarcity.

lento:  Italian for “slowly.”

Leq:  Equivalent sound Level.  The Leq of a sonic event is that constant SPL which has the

same amount of energy as the actual event.  Thus, the Leq is a long-term average, or integra-
tion, of an SPL.  It is approximately the average of the powers of instantaneous levels taken at
equal intervals over time during the measurement period.  Leq is a convenient way of accu-
rately measuring the level of a fluctuating sound over a range of a few seconds to several
hours.

Leslie cabinet:  A type of loudspeaker cabinet, developed by Don Leslie in the 1930’s and

used in electronic (especially Hammond) organs.  The sound from fixed transducers is dis-
persed via a rotating horn or (for bass speakers) an aperture in a rotating chute.  This causes a
continuously varying Doppler shift of the pitches in the audio signal, which mixes, with some
phase cancellation, to give a swirling, chorus-like effect.

Leslie simulator:  An effects unit which is intended to create the effect produced by a Leslie

cabinet.  It is similar to a chorus unit, but produces a richer effect.

level:  Loosely used when the magnitude of a signal is meant, usually voltage.  Strictly speak-

ing, the term should be reserved for the value of a power in dB.  The measured level of an
audio signal is the amplitude that is caused by the sum of the powers of all of the components
of the sound.

level control:  An envelope parameter which controls the level of certain synthesizer actions,

such as the sustain portion of an ADSR envelope.  Compare with rate control.

leveling:  The use of a compressor set to high ratios and very slow attack and release times.

With a digital recorder, it may be beneficial to have some kind of leveler followed by a proc-
essor that does peak-limiting.

level scaling:  See keyboard scaling.

level-sensing circuit:  An electronic circuit that generates a control voltage in proportion to

signal level.  This control voltage can then be used to affect the amount or type of signal
processing done by a separate device.  Also called a detector.

LFE:  Low Frequency Effect (film) or Low Frequency Enhancement (audio).  The subwoofer

channel signal in a 5.1 surround mix.  See in-band gain.

LFO:  Low Frequency Oscillator.  An oscillator whose output is infrasonic, typically used as a

control source for modulating the sound to create vibrato, tremolo, trills, and so on.  Unlike a
normal oscillator which produces audio signals, an LFO is a generator module that produces
a modulation/control signal.  The LFO’s signal output is in the form of a slow, periodic
waveform, usually less than 20Hz.  The most common parameters found in the LFO are
depth, frequency (rate control) and waveform selection.  See Appendix C.