The surround-sound format incorporating five discrete full-frequency audio channels and one discrete channel for low-frequency enhancement. See also 7.1 and surround sound.

The surround-sound format incorporating seven discrete full-frequency audio channels and one discrete channel for low-frequency enhancement. See also 5.1 and surround sound.

The format used in high-definition video where the camera is substituting for film. The 24 refers to the standard frames-per-second rate; the p stands for progressive.

Limit listening through headphones to no more than one hour per day at levels below 60 percent of maximum volume.

Used to pick up instruments in an ensemble when they solo. It is, in effect, a relatively close-miking technique but used when distant microphones are picking up the ensemble’s overall sound and a solo passage needs to stand out. Also known as off-miking. See also ambience miking, close miking, and distant miking.

See active combining network.

See MPEG.

See contact microphone.

The time relationship between two or more sound waves at a given point in their cycles.

The science that deals with the behavior of sound and sound control, including its generation, transmission, reception, and effects. The properties of a room that affect the quality of sound.

An amplifier at which the outputs of two or more signal paths are mixed together before being routed to their destination.

Allows amplification control of each audio source and usually includes other processing features as well. See also passive microphone mixer.

A ribbon microphone that uses an amplifier system requiring phantom power.

See sound envelope.

Internationally accepted professional digital audio interface transmitted via a balanced-line connection using XLR connectors, specified jointly by the Audio Engineering Society (AES) and the European Broadcast Union (EBU). See also Sony/Philips Digital Interface (S/PDIF).

Sounds such as reverberation, noise, and atmosphere that form a background to the main sound. Also called room tone and presence and, in Great Britain, atmos.

Used along with distant miking, attempts to reproduce the aural experience audiences receive in a live venue by recording in an acoustically suitable studio or concert hall. Microphones are positioned far enough from the ensemble where the later reflections are more prominent than the direct sound. See also accent miking, close miking, and distant miking.

A device that increases the amplitude of an electric signal.

The magnitude of a sound wave or electric signal, measured in decibels.

A signal processor that affects a signal’s loudness. The effects include compression, limiting, de-essing, expanding, noise gating, and pitch shifting. Also called dynamic processor.

A room that prevents all reflected sound through the dissipation or the absorption of sound waves.

The width-to-height proportions of a video image. For the standard video screen, it is 4 x 3 (1.33:1); for HDTV it is 16 x 9 (1.78:1). For wide motion picture screens, aspect ratios are between 5.55 x 3 (1.85:1) and 7 x 3 (2.35:1).

Short for atmosphere, the British term for ambience. See ambience.

(1) The way a sound begins—that is, by plucking, bowing, striking, blowing, and so on. (2) The first part of the sound envelope—how a sound starts after a sound source has been vibrated.

The length of time it takes a compressor to respond to the input signal.

See fader.

The relationship between sampling frequency and quantization. When audio is converted to digital, it becomes data. The data rate is computed by multiplying bit depth times sampling frequency.

See temporary threshold shift (TTS).

See psychoacoustic processor.

A pair of ungrounded conductors whose voltages are opposite in polarity but equal in magnitude.

A filter that attenuates above and below a selected bandwidth, allowing the frequencies in between to pass.

The difference between the upper and lower frequency limits of an audio component. The upper and lower frequency limits of AM radio are 535 kHz and 1,605 kHz; therefore, the bandwidth of AM radio is 1,070 kHz.

The curve shaped by the number of frequencies in a bandwidth and their relative increase or decrease in level. A bandwidth of 100 to 150 Hz with 125 Hz boosted 15 dB forms a sharp, narrow bandwidth curve; a bandwidth of 100 to 6,400 Hz with a 15 dB boost at 1,200 Hz forms a more sloping, wider bandwidth curve.

The low range of the audible frequency spectrum; usually from 20 to 320 Hz.

In surround sound, the redirection of low-frequency content from each of the full-bandwidth production channels to the low-frequency enhancement channel.

Attenuating bass frequencies. The control—for example, on a microphone—used to roll off bass frequencies.

See proximity effect.

See diaphragmatic absorber.

A microphone that picks up sound to its front and back and has minimal pickup at its sides.

Two omnidirectional capacitor microphones set into the ear cavities of an artificial head, complete with pinnae. This arrangement preserves binaural localization cues during recording and reproduces sound as humans hear it—three-dimensionally. Also called artificial head or dummy head (Kunstkopf) stereo.

See word length.

See pop filter.

High-density optical disc format developed to enable recording, playback, and rewriting of high-definition media.

Audio mixing console.

A microphone whose capsule is mounted flush with or close to, but a precise distance from, a reflective surface so that there is no phase cancellation of reflected sound at audible frequencies.

A compressor that acts on the dynamic range of the input signal across the entire frequency spectrum. See also split-band compressor.

A mixing network that combines the outputs of other channels.

Adjusting equipment—for example, a console and a recorder—according to a standard so that their measurements are similar.

A microphone that transduces acoustic energy into electric energy electrostatically. Also called condenser microphone.

A unidirectional microphone with a heart-shaped pickup pattern.

See recordable compact disc.

See rewritable compact disc.

In peak/dip equalizing, the frequency at which maximum boost or attenuation occurs.

In MIDI recording, the message that gives information on whether an instrument should send or receive and on which channel. It also indicates when a note event begins or ends and control information such as velocity, attack, and program change.

In MIDI recording, the message that facilitates response appropriate to monophonic, polyphonic, or polytimbral processing.

Transmits performance data throughout the MIDI system that are generated whenever the controller of a MIDI instrument is played.

See speed-up pitch shifting.

Recirculating the doubling effect to make one sound source sound like several. See also doubling.

Audible distortion that occurs when a signal’s level exceeds the limits of a particular device or circuit.

Placing a microphone close to a sound source to pick up mostly direct sound and reduce ambience and leakage. See also accent miking, ambience miking, and distant miking.

A psychoacoustic effect that allows humans to localize the sources of sounds around them.

Employing two matched microphones, usually unidirectional, crossed one above the other on a vertical axis with their diaphragms. See also X-Y miking.

The effect produced when a signal is time-delayed and added to itself, reinforcing some frequencies and canceling others, giving sound an unnatural, hollow coloration.

Descriptive sound that makes a comment or an interpretation. See also descriptive sound and narrative sound.

A contraction of the words com pressing and expanding that refers to wireless mics’ increasing dynamic range and reducing noise inherent in a transmission system.

Taking the best part(s) of each recorded track and combining them into a composite final version.

Equalizing sounds that share similar frequency ranges so that they complement, rather than interfere with, one another. See also cumulative equalization and subtractive equalization.

(1) Reducing a signal’s output level in relation to its input level to reduce dynamic range. (2) The drawing together of vibrating molecules, producing a high-pressure area. See also rarefaction.

The ratio of the input and output signals in a compressor.

The level at which a compressor acts on an input signal and the compression ratio takes effect.

A signal processor with an output level that increases at a slower rate as its input level increases.

See capacitor microphone.

A condition that occurs when there is damage to the eardrum or middle ear from disease; infection; excessive ear wax; foreign objects that block the eardrum; trauma to the head or neck; systemic disorders such as high- or low-blood pressure, vascular disorders, and thyroid dysfunction; and high doses of certain medications such as sedatives, antidepressants, and anti-inflammatory drugs.

An electronic device that amplifies, balances, processes, and combines input signals and routes them to broadcast or recording. Also called board, mixer, or, in Europe, mixing desk. See also mixer.

When sound waves are partially out of phase and partially additive, increasing amplitude where compression and rarefaction occur at the same time.

A microphone that attaches to a sound source and transduces the vibrations that pass through it. Also called acoustic pickup mic.

Provides tactual means of controlling various console-related functions. Generally there are no actual audio signals present inside a simple control surface— only control circuitry that sends digital instructions to the device doing the actual audio signal processing. Also called work surface.

A sample-based process that multiplies the spectrums of two audio files, providing a virtually infinite range of acoustic spaces.

See wireless microphone system.

The off-axis angle or point at which the loudspeaker level is down 6 dB compared with the on-axis output level.

Cycles per second. See hertz.

Fading in one sound source as another sound source fades out. At some point, the sounds cross at an equal level of loudness.

Too much boost of the same frequency in various tracks in a multitrack recording, which could unbalance the overall blend of a mix. See also complementary equalization and subtractive equalization.

(1) An instantaneous transition from one sound or picture to another. (2) To make a disc recording. (3) A decrease in level.

See hard sound effect.

See hertz.

See digital audio workstation.

See decibel.

See decibel full-scale.

See sound-pressure level.

How fast a sound fades from a certain loudness.

See reverberation time.

A relative and dimensionless unit to measure the ratio of two quantities.

A unit of measure for the amplitude of digital audio signals.

Reduces the high-frequency noise at the receiver in a wireless microphone system. See also pre-emphasis.

A compressor that reduces sibilance.

The time interval between a sound or signal and each of its repeats.

The amount of time between delays. In a digital delay, delay time regulates how long a given sound is held.

Describes sonic aspects of a scene not connected to the main action. See also commentative sound and narrative sound.

Has to be created because it does not exist in nature.

Permanently alters the original sound or soundfile. See also nondestructive editing.

When sound waves are partially out of phase and partially subtractive, decreasing amplitude where compression and rarefaction occur at different times.

A flexible panel mounted over an air space that resonates at a frequency (or frequencies) determined by the stiffness of the panel and the size of the air space. Also called bass trap.

Sound that comes from within the story space, such as dialogue and sound effects. See also nondiegetic sound.

The spreading of sound waves as they pass around an object, depending on the wavelength and distances involved.

The scattering of sound waves to a uniform intensity.

A multifunctional hard-disk production system, controlled from a central location, that is integrated with and capable of being networked to other devices, such as audio, video, and MIDI sources, within or among facilities. Generally, there are two types of DAW systems: computer-based and integrated.

The assembly of disk-based material in or out of sequence, taken from any part of a recording and placed in any other part of the recording almost instantly. Also known as nonlinear editing (NLE).

A microphone that converts an analog signal into a digital signal at the mic capsule.

Provides various manipulations of sound in a digital format. The term is generally used to refer to signal processing using computer software.

A compact disc providing massive data storage of digital-quality audio, video, and text.

Sound waves that reach the listener before reflecting off any surface. See also early reflections.

A surround-sound miking approach that uses a microphone array especially designed for surround-sound pickup. See also direct/ambient surround-sound miking.

A surround-sound miking technique using a stereo microphone array for the left-right frontal pickups, plus a center mic for the center channel and a stereo microphone array for the left- and right-rear surround pickup. See also direct surround-sound miking.

See unidirectional microphone.

Placing a microphone far enough from the sound source to pick up most or all of an ensemble’s blended sound, including room reflections. See also accent miking, ambience miking, and close miking.

The appearance of a signal in the reproduced sound that was not in the original sound. See also harmonic distortion, intermodulation distortion, loudness distortion, and transient distortion.

Multiple-antenna receiving system for use with wireless microphones.

Mixing slightly delayed signals (15 to 35 ms) with the original signal to create a fuller, stronger, more ambient sound. See also chorus effect.

(1) A sudden attenuation of sound or loss of picture. (2) Sudden attenuation in a wireless microphone signal due to an obstruction or some other interference.

A program that allows the transfer of audio signals to and from an audio interface.

A sound devoid of reverberation or signal processing. See also wet sound.

See digital signal processing.

Transferring sound from tape or disk to another tape or disk. Also called transfer.

How long a sound lasts.

See digital versatile disc.

See DVD-Audio.

A digital versatile disc format with extremely high-quality audio.

A microphone that transduces energy electromagnetically. Moving-coil and ribbon microphones are dynamic.

See amplitude processor.

The range between the quietest and the loudest sounds that a sound source can produce without distortion.

Reflections of the original sound that reach the listener within about 40 to 50 ms of the direct sound. Also called early sound. See also direct sound.

See early reflections.

Consists only of an earpiece with no headband cable-connected to a microphone.

Sound reflections delayed by 35 ms or more that are perceived as discrete repetitions of the direct sound.

The point in time at which an echo is perceived, generally between 1-30 ms following the direct sound.

A list of edits, computer-generated or handwritten, used to assemble a production.

See edit decision list.

The resonance of sound at particular frequencies in an acoustic space. May add unwanted coloration to sound. More commonly known as room modes.

The capacity to return to the original shape or place after deflection or displacement.

A capacitor microphone which, instead of requiring an external high-voltage power source, uses a permanently charged element and requires only a low-voltage power supply for the internal preamp.

The electrical manipulation of acoustics.

Equalization. See equalizer.

The principle that confirms the human ear’s nonlinear sensitivity to all audible frequencies: that midrange frequencies are perceived with greatest intensity and that bass and treble frequencies are perceived with lesser intensity.

A signal-processing device that can boost, attenuate, or shelve frequencies in a sound source or sound system.

See self-noise.

Designing an engineering system with human comfort and convenience in mind.

An amplifier whose gain decreases as its input level decreases. It increases dynamic range.

When a signal increases in amplitude from silence to the desired level over a period of time.

When a signal decreases to silence over a period of time.

A transition usually indicating a marked change in time, locale, continuity of action, and other features. It is effected by gradually decreasing the loudness of a signal level to silence (or to "black" in video) and then gradually increasing the loudness of a signal level from silence (or from "black").

A device containing a resistor that is used to vary the output voltage of a circuit or component. Also known as an attenuator, a gain or volume control, or a pot or potentiometer.

Monitoring sound at the listening position from large, powerful frontal loudspeakers several feet away and usually built into the mixing-room wall. See also near-field monitoring.

When part or all of a system’s output signal is returned into its own input. Feedback can be acoustic or electronic. A common example of acoustic feedback is the loud squeal or howl caused when the sound from a loudspeaker is picked up by a nearby microphone and reamplified. Electronic feedback is created in digital delay devices by feeding a proportion of the delayed signal back into the delay line. Also called regeneration.

A device that removes unwanted frequencies or noise from a signal.

A technology that enables isosynchronous service while providing the bandwidth needed for audio, imaging, video, and other streaming data. Isosynchronous service means it guarantees latency—the length of time between a requested action and when the resulting action occurs. FireWire offers a standard, simple connection to all types of electronics, including digital audio devices, digital VCRs, and digital video cameras as well as to traditional computer peripherals such as optical drives and hard-disk drives. FireWire can support up to 63 devices on a single bus.

See fundamental.

An equalizer with several fixed frequencies usually grouped in two (high and low), three (high, middle, and low), or four (high, high-middle, low-middle, and low) ranges of the frequency spectrum.

A wireless system assigned to one frequency. See also variable-frequency wireless microphone system.

Combining a direct signal and the same signal slightly delayed and continuously varying their time relationships, using a time delay.

Frequency response in an audio system that reproduces a signal between 20 Hz and 20,000 Hz (or between any two specified frequencies) that varies no more than ±3 dB.

Echoes between parallel walls that occur in rapid, even series.

See wireless microphone system.

The system in a multichannel console that permits the routing of sound through a headphone monitor feed to performers in the studio.

A frequency band in a voice or musical instrument that contains more energy and loudness than the neighboring area.

Frames per second.

The number of film frames that pass in 1 second of real time—frames per second (fps).

The number of times per second that a sound source vibrates, expressed in hertz (Hz); formerly expressed in cycles per second (cps).

A measure of an audio system’s ability to reproduce a range of frequencies with the same relative loudness; usually represented by a graph.

The lowest frequency a sound source can produce. Also called first harmonic and primary frequency.

See fader.

An equalizer with sliding controls that gives a graphic representation of the response curve chosen.

A sound reflection arriving up to 30 ms after the direct sound must be about 10 dB louder to be audible, resulting in the direct and reflected sounds’ being perceived as one. See also precedence effect.

Abrupt gain reduction at the start of compression. See also knee and soft knee compression.

Begins and ends cleanly requiring little adjustment in editing to remain in sync with the picture. Also known as a cut sound effect. See also soft sound effect.

Nonlinear distortion caused when an audio system introduces harmonics to a signal at the output that were not present at the input.

Frequencies that are exact multiples of the fundamental.

The filtering capacities of the head, outer ears, and torso in locating a sound in three-dimensional space. See diffraction and reflected sound.

The amount of increase in loudness level that a tape, amplifier, or other piece of equipment can take, above working level, before overload distortion.

Microphone attached to a pair of headphones; one headphone channel feeds the program and the other headphone channel feeds the director’s cues.

A resonator designed to absorb specific frequencies depending on size, shape, and enclosed volume of air. The enclosed volume of air is connected to the air in the room by a narrow opening, or neck. When resonant frequencies reach the neck of the enclosure, the air inside cancels those frequencies. Also called Helmholtz resonator.

Unit of measurement of frequency; numerically equal to cycles per second (cps).

In general, a very high-quality microphone. In particular, a trademark of Earthworks, Inc. referring to its line of these types of mics and its proprietary technology.

The treble range of the frequency spectrum.

A filter that attenuates frequencies below a selected frequency and allows those above that point to pass.

See head-related transfer function.

A hands-on device, such as a mouse, keyboard, joystick, or touchscreen, that facilitates control of computer functions.

A circuit built into a microphone to reduce hum pickup.

See hertz.

See interaural intensity difference.

The measure of the total resistance to the current flow in an AC circuit; expressed in ohms.

Sound level so quiet that it barely "kicks" the VU or peak meter.

Sound level so loud that the VU meter "rides" over 100 percent of modulation.

Sound waves that reflect from one or more surfaces before reaching the listener.

A microphone that allows fine adjustments to any on-axis response from omnidirectional through bi- and unidirectional pickup patterns.

The range below the frequencies audible to human hearing.

Pitches that are not exact multiples of the fundamental. See also overtones.

In the sound envelope, the point at which the attack begins to lose amplitude.

The part of the ear that contains the auditory nerve, which transmits sound waves to the brain.

On an in-line console, a module containing input, output, and monitor controls for a single channel.

On a console, the section into which signals from a sound source, such as a microphone, feed and are then routed to the output section.

A public telephone service that allows inexpensive use of a flexible, wide-area, all-digital network for, among other things, recording simultaneously from various locations.

The difference between signal intensity levels at each ear. Also known as interaural level difference (ILD).

See interaural intensity difference.

The difference between signal arrival times at each ear.

Nonlinear distortion that occurs when different frequencies pass through an amplifier at the same time and interact to create combinations of tones unrelated to the original sounds.

A standard based on the Internet Protocol (IP) for linking data storage devices over a network and transferring data by carrying SCSI commands over IP networks. See also Small Computer Systems Interface (SCSI) and Internet Protocol.

The acoustic situation in which the sound level changes in inverse proportion to the square of the distance from the sound source.

See input/output (I/O) module.

See Internet SCSI.

See Integrated Services Digital Network.

See interaural time difference.

Receptacle or plug connector leading to the input or output circuit of a patch bay, a recorder, or other electronic component.

A variation in time from sample to sample that causes changes in the shape of the audio waveform and creates adverse sonic effects such as reduced detail, harsher sound, and ghost imaging.

In digital editing, moving the mouse from side to side to direct control of an audio track. See also shuttling.

See kilohertz.

A measure of frequency equivalent to 1,000 hertz, or 1,000 cycles per second.

The point at which a compressor starts gain reduction. See also hard knee compression and soft knee compression.

Measuring system developed by Bob Katz that integrates measures of metering and monitoring to standardize reference loudness.

The period of time it takes for data to get from one designated point to another. In audio, the signal delay through the driver and the interface to the output.

Microphone that used to be worn around the neck but is now worn attached to the clothing. Also called mini-mic.

When many sounds occur at once, layering involves making sure sounds remain balanced, in perspective, and intelligible in the mix.

See low-frequency enhancement.

A compressor with an output level that does not exceed a preset ceiling regardless of the input level.

Having an output that varies in direct proportion to the input.

Usually in lengthy listening sessions, a pronounced dulling of the auditory senses, inhibiting perceptual judgment.

(1) Placement of a sound source in the stereo or surround-sound frame. (2) The direction from which a sound source seems to emanate in a stereo or surround-sound field. (3) The ability to tell the direction from which a sound is coming.

Repeating a sound continuously.

A data compression process during which no data is discarded. See also lossy compression.

A data compression process during which data that is not critical is discarded during compression. See also lossless compression.

The relative volume of a sound.

Distortion that occurs when the loudness of a signal is greater than the sound system can handle. Also called overload distortion.

Frequency range between roughly 20 Hz and 80 Hz, the lowest two octaves in the audible frequency spectrum.

The bass range of the frequency spectrum.

In a surround-sound system, using a separate channel and a subwoofer loudspeaker to reproduce low-frequency sounds.

A filter that attenuates frequencies above a selected frequency and allows those below that point to pass.

See Multichannel Audio Digital Interface.

A compression control that allows adjustment of the output level to the desired optimum. Used, for example, when loud parts of a signal are so reduced that the overall result sounds too quiet.

The hiding of some sounds by other sounds when each is a different frequency and they are presented together.

In a multichannel production console, the section that routes the final mix to its recording destination. It usually houses, at least, the master controls for the mixing bus outputs, reverb send and reverb return, and master fader.

The final preparation of audio material for duplication and distribution.

1,048,576 bytes (2²⁰ bytes); sometimes interpreted as 1 million bytes.

Measure of frequency equivalent to 1 million cycles per second.

A nonvolatile memory, such as Flash memory, that can be electrically recorded onto, erased, and reprogrammed. It does not need power to maintain the stored information.

A digital recorder that has no moving parts and therefore requires no maintenance. Uses a memory card as the storage medium.

See megahertz.

See microphone.

A transducer that converts acoustic energy into electric energy. Also called mic.

A device or plug-in that emulates the sound of various microphones.

The part of the ear that transfers sound waves from the eardrum to the inner ear.

Consists of two mic capsules housed in a single casing. One capsule, usually cardioid, is the midposition microphone. The other capsule, usually bidirectional, has each lobe oriented 90 degrees laterally.

See Musical Instrument Digital Interface.

Translates SMPTE time code into MIDI messages that allow MIDI-based devices to operate on the SMPTE timing reference.

The part of the frequency spectrum to which humans are most sensitive; the frequencies between roughly 320 and 2,560 Hz.

Boosting the level of an audience’s sound during laughter or applause and/or reinforcing it with recorded laughter or applause.

A unit of length equal to one thousandth (10^–3) of a meter, or 0.0394 inch.

One-thousandth of a second.

Short for miniature microphone. Any extremely small lavaliere mic designed to be unobtrusive on-camera and which can be easily hidden in or under clothing or on a set.

The point, usually in postproduction, when all the separately recorded audio tracks are sweetened, positioned, and combined into stereo or surround sound.

A small, highly portable device that mixes various elements of sound, typically coming from multiple microphones, and performs limited processing functions. See also console.

See console.

See millimeter.

Any of a number of different portable devices capable of storing and playing digital audio, video, and images, such as cell and smart phones, iPods, cameras, PDAs, and laptop computers.

The section in a console that enables the signals to be heard. The monitor section in multichannel production consoles, among other things, allows monitoring of the line or recorder input, selects various inputs to the control room and studio monitors, and controls their levels.

The continuous, seamless transformation of one effect (aural or visual) into another. It is a complete restructuring of two completely different and independent effects.

A mic with a moving-coil element. The coil is connected to a diaphragm suspended in a magnetic field.

Stands for Moving Picture Experts Group. A compression format for film established by the film industry and the International Standards Organization (ISO). Uses an analytical approach to compression called acoustic masking.

See millisecond.

See middle-side microphone.

See MIDI time code.

See multiple.

The standard used when interfacing multichannel digital audio.

Microphone with more than one pickup pattern. Also called polydirectional microphone.

In wireless microphones, when more than one radio frequency (RF) signal from the same source arrives at the receiver’s front end, creating phase mismatching.

(1) On a patch bay, jacks interconnected to each other and to no other circuit. They can be used to feed signals to and from sound sources. Also called mults. (2) An amplifier with several mic-level outputs to provide individual feeds, thereby eliminating the need for many. Also called a press bridge or a presidential patch.

A mic that has more than one opening for sound waves to reach the transducer. Most of these openings are used to reject sound from the sides or back of the microphone through phase cancellation. Each port returns a different frequency range to the mic capsule out of phase with sounds reaching the front of the mic. Also called variable-D.

A protocol that allows synthesizers, drum machines, sequencers, and other signal-processing devices to communicate with or control one another or both.

Sound effects that add more to a scene than what is apparent and so perform an informational function. See also commentative sound and descriptive sound.

See noise criteria.

A stereo microphone array in which the mics are separated horizontally but the angle or space between their capsules is not more than several inches, depending on the ensemble’s width. See also X-Y miking.

Monitoring with loudspeakers placed close to the operator, usually on or just behind the console’s meter bridge, to reduce interference from control room acoustics at the monitoring position. See also far-field monitoring.

Any unwanted sound or signal.

Headphone that detects ambient noise before it reaches the ears and nullifies it by synthesizing the sound waves.

A microphone designed for use close to the mouth and with excellent rejection of ambient sound.

Contours of the levels of background noise that can be tolerated within an audio studio.

An expander with a threshold that can be set to reduce or eliminate unwanted low-level sounds, such as room ambience, rumble, and leakage, without affecting the wanted sounds.

See sound absorption coefficient.

Editing that does not alter the original sound or soundfile, regardless of what editing or signal processing is affected. See also destructive editing.

Sound outside the story space such as music underscoring. See also diegetic sound.

See omnidirectional microphone.

The property of not being linear—not having an output that varies in direct proportion to the input.

See digital editing.

A filter capable of attenuating an extremely narrow bandwidth of frequencies.

See sound absorption coefficient.

The interval between two sounds that have a frequency ratio of 2:1.

Not being within the optimal pickup pattern of a microphone; off-axis.

See accent miking.

Microphone that picks up sound from all directions. Also called nondirectional microphone.

Being within the optimal pickup pattern of a microphone; on-axis.

A device that generates pure tones or sine waves.

The portion of the ear that picks up and directs sound waves through the auditory canal to the middle ear.

In a mixer and console, the section that routes the signals to a recorder or broadcast or both.

Feeding a component or system more amplitude than it can handle and thereby causing loudness distortion.

See loudness distortion.

On a console, a light-emitting diode (LED) that flashes when the input signal is approaching or has reached overload and is clipping. Also called peak indicator.

An attenuator inserted into a component or system to reduce level.

Short for panoramic potentiometer. A volume control that shifts the proportion of sound from left to right between two output buses and, hence, between the two loudspeakers necessary for reproducing a stereo image, or among the six (or more) surround-sound channels, and loudspeakers, necessary for reproducing a surround-sound image.

A system that uses a concave dish to focus reflected sound into a microphone pointed at the center of the dish.

An equalizer that combines the features of a parametric and a graphic equalizer.

An equalizer in which the bandwidth of a selected frequency is continuously variable.

A microphone that does not require phantom power.

Combines individual inputs into one output without amplifying the signal. See also active microphone mixer.

An assembly of jacks to which are wired the inputs and the outputs of the audio components in a console and/or sound studio. Also called patch panel.

A short cord or cable with a plug at each end, used to route signals in a patch bay.

See patch bay.

See overload indicator.

A meter designed to indicate peak loudness levels in a signal.

A meter designed to indicate transient peaks in the level of a signal.

The percentage of an applied signal in relation to the maximum signal a sound system can handle.

Establishing through mic-to-source distance the audio viewpoint in relation to the performers and their environment in screen space.

See solo.

Operating voltage supplied to a capacitor microphone by an external power source or mixer, thereby eliminating the need to use batteries.

The time relationship between two or more sounds reaching a microphone or signals in a circuit. When this time relationship is coincident, the sounds or signals are in phase and their amplitudes are additive. When this time relationship is not coincident, the sounds or signals are out of phase and their amplitudes are subtractive.

See polarity reversal.

The phase relationship of two signals at a given time, or the phase change of a signal over an interval of time.

An effect created by splitting a signal in two and time-delaying one of the signal portions, using a phase shifter.

See polar response pattern.

The subjective perception of frequency—the highness or lowness of a sound.

A signal processor that varies the pitch of a signal. The basic parameter for pitch shifting is transposition.

An add-on software tool that gives a hard-disk recording/editing system signal processing alternatives beyond what the original system provides. Available separately or in bundles.

The relative position of two signal leads—the high (+) and the low (-)—in the same circuit.

The control on a console that inverts the polarity of an input signal 180 degrees. Sometimes called phase reversal.

The indication of how a loudspeaker focuses sound at the monitoring position(s).

The graph of a microphone’s directional characteristics as seen from above. The graph indicates response over a 360-degree circumference in a series of concentric circles, each representing a 5 dB loss in level as the circles move inward toward the center. Also called pickup pattern.

See multidirectional microphone.

Foam rubber windscreen placed inside the microphone head. Particularly effective in reducing sound from plosives and blowing. Also called blast filter. See also windscreen.

A sound absorber made up of porous material whose tiny air spaces are most effective at absorbing high frequencies.

Short for potentiometer. See fader.

See fader.

See peak program meter.

The tendency to perceive the direct and immediate repetitions of a sound as coming from the same position or direction even if the immediate repetitions coming from another direction are louder. See also Haas effect.

The amount of time between the onset of the direct sound and the appearance of the first reflections.

See solo.

(1) Boosts the high frequencies in wireless microphone transmission. See also de-emphasis. (2) Boosts the treble range in radio broadcast transmission by 6 dB per octave, starting at 2.1 kHz (in the United States) or 3.2 kHz (in Europe).

(1) Mixing groups of similar voicings, such as strings, backup vocals, and the components of a drum set before routing them to a master channel(s). (2) The stage in postproduction when dialogue, music, and sound effects are prepared for final mixing.

(1) Perception of a sound as being close and realistic. (2) Also used as a synonym for ambience and room tone. See ambience.

See fundamental.

Increase in the bass response of some mics as the distance between the mic and its sound source is decreased. Also known as bass tip-up.

Used for body miking; tends to add presence to close dialogue and reject background sound. See also transparent mini-mic.

Signal processor that adds clarity, definition, overall presence, and life, or "sizzle," to recorded sound.

The study of human perception of and subjective response to sound stimuli.

A single frequency devoid of harmonics and overtones.

A measure of the bandwidth of frequencies an equalizer affects.

Converting a waveform that is infinitely variable into a finite series of discrete levels.

See wireless microphone system.

Temporary drawing apart of vibrating molecules, causing a partial vacuum to occur. See also compression (2).

Mode of operation in an automated mixdown when the console controls are operated automatically by the data previously encoded in the computer. Also called safe mode. See also update mode and write mode.

A CD format allowing users to record one time but to play back the recorded information repeatedly.

See release time.

Reflections of the direct sound that bounce off one or more surfaces before reaching the listener.

See feedback.

In the sound envelope, the time and the manner in which a sound diminishes to inaudibility.

The length of time it takes a compressor to return to its normal level (unity gain) after the signal has been attenuated or withdrawn. Also called recovery time.

The final stage in postproduction, when the premixed tracks or stems—dialogue, music, and sound effects—are combined into stereo and surround sound and sent to the edit master.

See word length.

Transmitting a vibration from one body to another when the frequency of the first body is exactly, or almost exactly, the natural frequency of the second body.

Multiple blended, random reflections of a sound wave after the sound source has ceased vibrating. The types of reverberation in current use are digital, convolution, plate, and acoustic chamber. Also called reverb and reverberant sound.

The length of time it takes a sound to die away—the time it takes a sound to decrease to one-millionth of its original intensity, or 60 dB-SPL. Also called decay time.

A compact disc format that can be recorded on, erased, and used again for another recording.

The sonic time pattern.

A microphone with a ribbon diaphragm suspended in a magnetic field.

Continually adjusting controls on a console or other audio equipment to maintain a more or less constant level.

See eigentones.

Another term used for ambience. Also called presence. See ambience.

See sound absorption coefficient.

See read mode.

See word clock.

(1) Examining an analog signal at regular intervals defined by the sampling frequency. (2) A process whereby a section of digital audio representing a sonic event, acoustic or electroacoustic, is stored on disk or into electronic memory.

The frequency (or rate) at which an analog signal is sampled. Also called sampling rate.

In hard-disk editing, moving the play cursor through the defined region at any speed to listen to a sound being readied for editing.

See Small Computer Systems Interface.

(1) Cutting from one effect to another with nothing in between. (2) Playing two recordings one after the other, with no announcement in between.

The electrical noise, or hiss, an electronic device produces. Also called equivalent noise level.

(1) Measurement of the voltage (dBV) a microphone produces, which indicates its efficiency. (2) The sound-pressure level directly in front of the loudspeaker, on-axis, at a given distance and produced by a given amount of power.

A nerve-based condition that occurs when the microscopic hair cells of the inner ear are compromised or damaged.

An electronic device that can be programmed to store and automatically play back a repeating series of notes on an electronic musical instrument such as a synthesizer.

See sound effects.

Maximum boost or cut of a signal at a particular frequency that remains constant at all points beyond that frequency so the response curve resembles a shelf.

A device that isolates a microphone from mechanical vibrations. It can be attached externally or built into a microphone.

A highly directional microphone with a tube that resembles the barrel of a rifle.

Devices used to alter some characteristic of a sound. See also amplitude processor, spectrum processor, and time processor.

The ratio, expressed in decibels, of an electronic device’s nominal output to its noise floor. The wider the S/N ratio, the better.

A fundamental frequency with no harmonics or overtones. Also called pure tone.

A directional microphone that uses a single port to bring sounds from the rear of the mic to the capsule. Because these sounds from the rear reach the capsule out of phase with those that reach the front of the capsule, they are canceled. Also called single-D microphone.

The effect created when an original signal repeats as distinct echoes that decrease in level with each repetition.

The part of a talkback system that feeds sound to a recording. It is used for verbal identification of the material recorded, the take number, and other information just before each recording.

The standard for hardware and software command language that allows two-way communication between, primarily, hard-disk and CD-ROM drives. Pronounced "scuzzy."

A reference in hours, minutes, seconds, and frames used for coding to facilitate editing and synchronization. Pronounced "sempty."

See signal-to-noise ratio.

Term used with picture when a shot change is brief but not quite as abrupt as a cut nor as deliberate as a dissolve. The effect can be used in audio for transitions that need a quick, yet aesthetically, graceful change.

Smooth gain reduction at the start of compression. See also knee and hard knee compression.

Does not have a defined beginning and ending and does not explicitly synchronize with the picture. See also hard sound effect.

A control on a multichannel console that automatically cuts off all signals feeding the monitor system except those signals feeding through the channel that the solo control activates. Sometimes called prefader listen (PFL).

The consumer version of the AES/EBU interface calling for an unbalanced line using phono connectors. See also AES/EBU.

A measure of the sound-absorbing ability of a surface. This coefficient is defined as the fraction of incident sound absorbed by a surface. Values range from 0.01 for marble to 1.00 for the materials used in an almost acoustically dead enclosure. Also known as noise reduction coefficient (NRC).

Computer hardware necessary to input, manipulate, and output audio.

The audio components that carry a signal from its sound source to its destination.

The process of creating the overall sonic character of a production (usually in relation to picture).

Anything sonic that is not speech or music.

Changes in the loudness of a sound over time, described as occurring in four stages: attack, initial decay, sustain, and release (ADSR).

A sound stored in the memory of a hard-disk recorder/editor.

The range of frequencies audible to human hearing: about 20 Hz to 20,000 Hz.

A measure of the pressure of a sound wave, or sound-pressure level (SPL), expressed in decibels (dB).

A rating that evaluates the effectiveness of barriers in isolating sound.

A vibrational disturbance that involves mechanical motion of molecules transmitting energy from one place to another.

Background music from an on-screen source such as a stereo, radio, or jukebox. It is added during postproduction.

Two, sometimes three, microphones spaced from several inches to several feet apart, depending on the width of the sound source and the acoustics, for stereo recording.

See Sony/Philips Digital Interface.

Using a sonogram view of an audio file to facilitate ultra-fine surgical editing.

A signal processor that affects a sound’s spectral range such as equalizers, filters, and psychoacoustic processors.

Changes the timbre and pitch of natural sounds. Sometimes referred to as the chipmunk effect.

See sound-pressure level.

A compressor that affects an input signal independently by splitting the audio into multiple bands and then recombining the outputs of the bands into a single mono or stereo broadband signal. See also broadband compressor.

In a wireless microphone system, a process of signal reception at the receiver that silences or mutes the receiver’s audio output when there is no radio signal.

See sound transmission class.

One-dimensional sound that creates the illusion of two-dimensional sound.

Two directional microphone capsules, one above the other, with separate outputs, encased in one housing.

Attenuating, rather than boosting, frequencies to achieve equalization. See also complementary equalization and cumulative equalization.

Multichannel sound, typically employing six or more channels, each one feeding to a separate loudspeaker that expands the dimensions of depth, thereby placing the listener more in the center of the aural image than in front of it. See also 5.1 and 7.1.

Separate microphones, or microphone capsules, housed in a single casing, for each pickup in a given surround-sound format and a controller to adjust spatial imaging.

In the sound envelope, the period during which the sound’s relative dynamics are maintained after its initial decay.

In control room monitoring, the designated listening position, which is the optimal distance away from and between the loudspeakers.

Enhancing the sound of a recording in postproduction through signal processing and mixing.

Locking two or more devices that have microprocessor intelligence so that they operate at precisely the same rate.

In a MIDI system, the message that affects an entire device or every device regardless of the MIDI channel. It gives timing information, such as what the current bar of the song is and when to start and stop, as well as clocking functions that keep a MIDI sequencer system in sync.

Interchangeable microphone capsules of various directional patterns that attach to a common base. The base contains a power supply and a preamplifier.

Studio-address intercom system that permits communication from a control room microphone to a loudspeaker or headphones in the studio.

The speed of a sound.

A reversible desensitization in hearing that disappears in anywhere from a few hours to several days. Also called auditory fatigue.

1,024 gigabytes (2⁴⁰ bytes).

Stands for total harmonic distortion.

A guideline used to reduce the phasing caused when a sound reaches two microphones at slightly different times. It states that no two mics should be closer to each other than three times the distance between one of them and its sound source.

120 dB-SPL.

The lowest sound-pressure level at which sound becomes audible to the human ear. It is the zero reference of 0 dB-SPL.

The sound-pressure level at which the ear begins to feel pain, about 140 dB-SPL, although levels of around 120 dB-SPL cause discomfort.

Facilitates the interconnecting of outboard devices and patch bays in a control room or between studios.

The unique tone quality or color of a sound.

Shortening the time (length) of material without changing its pitch.

Increasing the time (length) of material without changing its pitch.

A signal processor that affects the time interval between a signal and its repetition. The effects include reverberation and delay.

After prolonged exposure to loud sounds, the ringing, whistling, or buzzing in the ears, even though no loud sounds are present.

See transmission loss.

A device that converts one form of energy into another.

See dub.

A sound that begins with a sharp attack followed by a quick decay.

Distortion that occurs when a sound system cannot reproduce sounds that begin with sudden, explosive attacks.

The amount of sound reduction provided by a barrier such as a wall, floor, or ceiling.

See wireless microphone system.

Used for body miking; tends to add an open, natural sound and pick up more ambience. See also proximity-prone mini-mic.

Frequency range between roughly 5,120 Hz and 20,000 Hz, the highest two octaves in the audible frequency spectrum.

(1) To attenuate the loudness level in a component or circuit. (2) The device on a console that attenuates the loudness level at the microphone/line input.

See temporary threshold shift.

A capacitor microphone using a tube circuit in the preamp.

Frequencies above the range of human hearing.

A line (or circuit) with two conductors of unequal voltage.

Nondiegetic music added to enhance the informational or emotional content of a scene.

A microphone that picks up sound from one direction. Also called directional microphone.

Mode of operation in an automated mixdown when an encoded control can be recorded without affecting the coding of the other controls. See also read mode and write mode.

Frequency range between roughly 80 Hz and 320 Hz.

Frequency range between roughly 2,560 Hz and 5,120 Hz.

A digital microphone developed for those who want to record directly into a computer without an audio interface such as a console, control surface, or mixer. USB stands for Universal Serial Bus.

See USB microphone converter.

Device that makes it possible to connect any dynamic or capacitor XLR microphone into a computer via USB. Also known as a USB microphone adapter.

A wireless microphone system that can use more than one channel. Also known as frequency-agile system. See also fixed-frequency wireless microphone system.

The speed of a sound wave: 1,130 feet per second at sea level and 70°F.

In hard-disk recording, a track that provides all the functionality of an actual track but cannot be played simultaneously with another virtual track.

Technology that allows interactive video game users who have a headset and a microphone to speak with each other, give and receive instructions, and play in a team environment against others using the same technology.

A device that can enhance, modify, pitch-correct, harmonize, and change completely the sound of a voice. Also called vocal processor.

See Voice over Internet Protocol.

See fader.

A meter that responds to the average voltage on the line, not true volume levels. It is calibrated in volume units and percentage of modulation.

See volume-unit meter.

A graphic representation of a sound’s characteristic shape displayed, for example, on test equipment and hard-disk editing systems.

The length of one cycle of a sound wave. Wavelength is inversely proportional to the frequency of a sound; the higher the frequency, the shorter the wavelength.

A sound with reverberation or signal processing. See also dry sound.

Foam rubber covering specially designed to fit over the outside of a microphone head. Used to reduce plosive and blowing sounds. See also pop filter.

System consisting of a transmitter that sends a microphone signal to a receiver connected to a console or recorder. Also called cordless, FM, radio, and transmitter microphone.

A synchronization signal used to control the rate at which digital audio data is converted or transmitted. Also called sample clock or digital clock.

Describes the potential accuracy of a particular piece of hardware or software that processes audio data. In general, the more bits available, the more accurate the resulting output from the data being processed. Also called bit depth and resolution.

See control surface.

The mode of operation in an automated mixdown during which controls are adjusted conventionally and the adjustments are encoded in the computer for retrieval in read mode. See also read mode and update mode.

Common male and female microphone plugs with a three-pin connector.

Coincident or near-coincident miking that places the microphones’ diaphragms over or horizontal to one another. See also coincident miking and near-coincident miking.

The point in a waveform denoting a value of zero amplitude. It divides the positive (upper) and negative (lower) parts of the waveform.