Audio-Visual Glossary



EARLY REFLECTIONS: In sound, these are the first reflections of sound hitting a room’s walls, ceiling or floor which then bounce and come to the listener. For example, when listening to loudspeakers, one hears their direct sound. One can also hear sound bouncing off the walls of the room. The first of those reflections one hears are the “early reflections”.


EAR PIECE, EAR SPEAKER: Any small device actually placed in the ear for audio program to be heard.


EARTH: This is British for “ground”. (See GROUND.)


EARTH LOOP: British for “ground loop”. (See GROUND LOOP.)


EARTHY: In audio, an instrument’s live sound, or any recorded or mixed sound is said to sound “earthy” when it sounds natural and non artificial.


EARWIG: A small earpiece which is used to give actors or singers sound they can sing or talk along with.


EASE: “Ease” pertains to reproduced sound when it has not been compressed and its qualities do not sound strained. The sounds have an ease about them. It is enjoyable to listen to.


EASY TO LISTEN TO: When the audio is not blasting or uncomfortable on the ears. Some recorded and-or reproduced sounds can be piercing and actually hurt the ears.


EAW: Eastern Acoustics Works. A company that manufactures loudspeakers and amplifiers for PA systems.


eBOOK: An abbreviation for electronic books, a recent format for books. eBooks can be read using laptops, desktops, palm tops and pocket PC’s. Many published titles are available in the eBook format. The books can be downloaded from the Internet as well as by taking one’s computer to bookstores and downloading from in-store computers. One of the most popular eBook formats is Rocket eBook, which lists hundreds of science fiction and fantasy titles. Another major eBook publisher is, which sells eBooks for palm tops.


eBOOK PLAYER: A handheld electronic device that is specially designed and built to display e-Books (electronic books). (See eBOOK.)


EBU: European Broadcast Union. An organisation comprising European broadcasters to coordinate production and technical standards of European broadcasting.


ECC: (Error Correction Coding) A digital code which has the ability to correct errors in a digital audio or video program.


ECHO CHAMBER: An enclosed room with hard walls, ceiling and floor, which reflect sound. An echo chamber is used in the mixing of lectures, music and other audio products. A basic echo chamber is created by placing a loudspeaker within a room predominately made of hard reflective surfaces. Within the room is also placed a microphone. Sound is played over the loudspeaker. Its sound reflects off the walls, ceiling and floor. Those echoes (reflections) continue until all echo dies out. While doing so, the microphone picks up all this sound within the echo chamber and that sound is sent to the mixboard where the Mixer can add it into his mix. Because the echo in the chamber is naturally created by real reflections, it sounds very realistic. When added to the mix, it is as though the sound was originally performed in a large, room, hall or on stage in an auditorium. All these combined reflections of sound within the room are called “reverberation”. The design of each chamber is calculated using the physics of sound as related to room dimensions. Every chamber has four speakers inside and each speaker can be delayed in time relative to each other. Just as different sized halls have longer and shorter delay times (the time it takes a sound to reach a surface, such as a wall, reflect, and then be heard by a listener in the hall). Several microphones are precisely positioned within the chambers to pick up all aspects of the reverberation produced. These are then blended together to give a realistic quality to the sounds being mixed in the studio.


ECHOEY, ECHOIC: Pertaining to an acoustical space having excessive reverberation. Hard surfaces in recording and-or listening rooms will result in a lot of reflections and generally echoic sound.


ECHOPLATE: A type of reverb device. A large metal sheet is suspended on spring clips and driven like a loudspeaker cone. The tendency of the device is to continue to vibrate, repeating the sounds it has received, after the sound input signal ceases. Microphones near the plate pick up the plate’s sound and send it to the mix room where the echoplate’s sound can be added to the mix.


ECHO SEND: One of the outputs of a mixboard specifically used to send a signal to an echo chamber, reverb unit or delay effects device when mixing live or in the studio.


ECHO RETURN: An input on a mixboard used to bring back the echo (reverberation) signal from the echo chamber or other reverberation device.


ECHOSTAR: The name of a digital satellite company, located in Denver Colorado, which owns several telecommunications satellites.


ECM: Abbreviation for Electret Condenser Microphone. (See ELECTRET and CONDENSER MICROPHONE.)


ECM 50: A model of lapel microphone made by the Sony Corporation.


ECN: Abbreviation for Eastman Colour Negative. This is a term sometimes used in the film industry to mean the original camera negative. (See ORIGINAL CAMERA NEGATIVE.) The “Eastman” refers to Eastman-Kodak film and has become a generic term in the film industry.


EDGE AMPLIFIER: A brand of audio amplifier of very high quality. Some models of Edge amplifiers employ the use of lasers inside the amplifier to enable the amp to continuously adjust itself for optimum performance. They are made in Denver, Colorado.


EDGE CODE, KEY CODE: Also referred to as “edge numbers”. These are written numbers applied by a film manufacturer to the original camera negative film. Edge code numbers are printed outside the sprocket holes on film. They are used as a reference for film footage and also to locate specific film frames. They enable the film’s editor and negative cutter to locate the precise frames upon which they must cut and splice to assemble the film per the approved edit.


EDGE TRACK: The outside tracks of a multitrack audio recording tape. Example, tracks 1 and 24 of a 24 track master recording. These are the areas of tape most susceptible to physical damage.


EDGY: Sound which is undesirably trebly. It’s as if you might view the sound on test equipment and see its waveform looking jagged due to excessive high frequencies that have little sharp peaks. “Edgy” sound is somewhat distorted and has unwanted characteristics which add a raspiness to the sound. The sound’s quality is sharp, like the edge of a blade and can set the listener “on edge”.


EDISON: A type of connector for mains power, named after inventor Thomas Edison.


EDIT BAY, EDITING BAY: The word “bay” means any compartment or space which is sectioned off for its own purpose or function. It comes from the French word meaning “an opening in a wall”.




EDITING, TO EDIT, AN EDIT: 1) The process of selecting from a large amount of recorded material (audio or visual) and assembling a final program by combining desired footage in sequence so as to create a final product. 2) Putting portions of a program into a new sequence. 3) Taking out unwanted sounds or picture content. Removing objectionable portions. 4) Removing or adding content so a product is appropriate for a specific public.


EDITING BUMP: When editing analogue audio tape (cutting the tape so as to remove unwanted sounds or to put together a complete performance), if the editor is not careful, he can create a sudden “bump” sound where the edit (cut) is made. This can be caused by a number of factors. Sometimes, the edit left in a very small bit of the unwanted sound so it causes a “bump” when played. An editing bump can occur when editing digitally on computer as well for similar reasons - such as a small bit of an unwanted sound missed (left in) or where the background ambient noise of a recording suddenly jumps louder where the edit is done because the volumes of the two shots was not matched prior to the edit.


EDL: Abbreviation for Edit Decision List. 1) A list of the decided edits for a video or film. It is a list of each “cut” (edit) made, giving the frame number of the video or film. An EDL is used by the on-line bay to do the final video assembly and an EDL is also used, when editing a film, to prepare the Work Print and to cut and assemble the original negatives after the film’s edit is fully approved. 2) This is a term used in the SADiE digital audio computer manual. When an edit is done in SADiE, the computer stores the exact edit points (the points the edit started and ended). It stores these in memory as a set of instructions so it can be played back or further edited.


EDL CONVERSION: This is a term used in the SADiE digital audio computer manual. A feature on the SADiE system that allows the operator to convert a SADiE EDL to and from EDLs made on other computerised editing equipment.


EDL ENTRY: This is a term used in the SADiE digital audio computer manual. (Clear the terms EDL, CLIP, PLAYLIST, CLIPSTORE to fully understand this definition.) When using the SADiE system, clips (sections of audio program) are placed in the Playlist. When this is done, they become EDL entries (EDL = Edit Decision List) as they then have a particular EDL replay time. Any changes made to an EDL entry (such as volume changes or adjustments to the in and out points of an edit) only then apply to that particular section of the soundtrack and will not affect the other clips in the Clipstore, or other EDL entries of the same Clip. Editing is done by making “cuts” which divide entries into two, so that one or the other can be removed, or the in and out points can be adjusted to fine edit the audio.


EDS: Abbreviation for Eighth Day Sound (Company). A professional audiovisual equipment rental company located in Cleveland, Ohio.


E - E: See E TO E.


EEPROM or E2PROM: (Electrically Erasable Programmable Read-Only Memory) A version of read-only memory (ROM) that can be electrically erased and reprogrammed by the designer. Differentiated from standard EPROM (one "E") which requires ultraviolet radiation for erasure.  


EFFECTIVE MASS: A measurement of how a phonograph’s tonearm resists motion - its own friction preventing it from moving easily across the record as it plays. Tonearms must move freely to follow the groove of a record, and lighter tone arms usually perform this task better than heavy ones.


EFFECTS (audio mixing): Various ways an audio signal can be modified by adding something to the signal or changing qualities of its sound. Common effects are reverberation and delay. Effects are used in mixing music in the studio or live. Can also be used as a noun to refer to the many different electronic mixing devices which create such effects.


EFFECTS DEVICES, EFFECTS BOX, EFFECTS EQUIPMENT: A unit designed to add effects (such as reverberation or delay effects) to an audio signal. Used in mixing in the studio or live.


EFFECTS RACK(S): The cabinets (racks) which, in a mixing control room, house the various effects devices such as reverb units, delay units, etc.


EFFECTS RETURNS: The input connectors as well as the various controls on an audio mixboard into which are routed the audio signals returning from effects equipment which has processed the sound(s).


EFFECTS SEND: The output connectors as well as the various controls on an audio mixboard from which audio signals are sent to effects equipment (such as reverberation or delay devices) intended to process the sound.


EFFICIENCY: The percentage of the electrical input power to a loudspeaker that is converted to acoustic energy and able to be heard. Highly efficient speakers can be powered by a lower strength amplifier. Inefficient loudspeakers require more amplifier strength to play them at acceptable volume levels. Note that efficiency indicates nothing about sound quality, only quantity of acoustic energy for a given amount of input power. A more common way of expressing speaker efficiency is to use the word “sensitivity” - how “sensitive” the loudspeaker is to a given amount of amplifier power.


EFFORTLESS: If a loudspeaker or audio electronic equipment can play the loud, very dynamic parts with ease and not strain, and without restricting them, then it is said to be “effortless”. They sound like they could handle even more power and volume.



1) Extra-Fine Particle. This is a designation that appears on the boxes of some types of ½ inch VHS recording tape. “EFP” refers to the magnetic particles that comprise the magnetic particle coating of the tape. The label is a statement by the manufacturer that the tape is higher quality than common VHS tape. The EFP designation is usually found on TDK and Sony ½ inch VHS video cassettes.

2) EFP is also an abbreviation for Electronic Field Production. This is the use of high quality video cameras to shoot exterior location scenes. Electronic = video (instead of using film cameras). Field = on location (as opposed to shooting in a studio). Modern TV-video technology has developed video camera systems which are portable enough to be used for location shooting. Production = the action of shooting the scenes of a movie, TV show, etc. (but not the editing, sound mixing or other post production stages).


EIA: (Electronic Industries Association) Founded in 1924. The EIA is a private trade organisation made up of electronics manufacturers that sets standards for voluntary use of its member companies (and all other electronic manufacturers), conducts educational programs, and lobbies in Washington for its members' interests. It is responsible for the development and maintenance of industry standards for the interfaces between data processing machines and data communication equipment.


EIDE: Acronym for Enhanced Intelligent Drive Electronics. Most personal computers have this type of connection point for use in hooking up to different pieces of computer equipment and transferring information. Another connection especially used for audiovisual computer information is called “SCSI” (pronounced “skuzzy”). SCSI means Small Computer Systems Interface. EIDE is less expensive than SCSI, but it is also slower in its operation.


EIGENTONE: Unwanted sound resonance and reflections of coming off a room’s walls, ceiling and floor which fight each other to the point where pockets of built-up sound are literally “standing” in the room, unable to move freely and rapidly dissipate. Such pockets get created between two parallel room surfaces. This term comes from the German word “eigenvektor”, meaning “characteristic vector”, and describes the motion and reflections of sound in an enclosed space. The frequency of the pocket of built-up sound is determined by the distance between the parallel surfaces. Any listening room with parallel surfaces runs the risk of building up such pockets.




8.1 SURROUND: This is Sony’s big surround sound system for major general cinema theatre use. See SDDS for full details.


8761: This is the type of grey wire used commonly for audio installations. Made by Belden.


8 TRACK: This was a large rectangular tape cassette that has long since died out as a music format. Its name is still in use to refer to new audio formats that come and go - or probably will go. “Digital Cassette Recorders went the way of the 8 track.”




8VSB: Abbreviation for 8-level Vestigial Side Band. This is the name of a Digital Television (DTV) broadcast standard for the U.S. and Canada. (See VSB for complete definition.)


EIKI PROJECTOR: The brand of 16 millimetre film projector for playing tech and public films in orgs.


EK: Stands for EASTMAN KODAK, a manufacturer of photographic and movie film.


EK NEG, (EKN): This is a film industry colloquial expression for “original camera negative”. “EK” stands for “Eastman Kodak”, although the term is somewhat generic and thus used regardless of whether or not the shot was actually photographed on Eastman Kodak stock. The original camera negative is also called “OCN”.




ELECTRET: A piece of plastic that has a permanent static charge of electricity built into it. It is used inside of some condenser microphones so that battery power doesn't have to be used to charge the diaphragm of the microphone. (Power is, however, needed to operate the electret microphone’s electronic circuit.)


ELECTRO-ACOUSTIC GUITAR: The “electro-acoustic” guitar looks like an electric guitar but it has a slightly deeper body and a hole under the strings like a conventional acoustic guitar. The electro-acoustic was made for electric guitarists who are used to the easy playability and size of an electric as opposed to the heavy strings of a real acoustic guitar. Also, the electro-acoustic tends to have fewer feedback problems on stage compared to trying to put a microphone or pick-up on a real acoustic. It is principally used for performing live as normal acoustic guitars are prone to feedback.


ELECTRODE: Either of the two conducting elements through which a current enters or leaves. Broadly, a collector or emitter of electricity. Electrode comes from the Greek words meaning a way or path for electricity.


ELECTROHOME ROADIE: Electrohome is the name of a company that manufactures professional video projectors. The “Electrohome Roadie” is a large and powerful analogue video projector.


ELECTROLYSIS: The word “electrolysis” comes from Latin, meaning “breaking down by electricity”. It is a chemical process that uses electricity to break a metallic chemical compound down into its basic parts so that the metal can be deposited onto another surface so as to give that surface a coating. For example, a solution of “copper sulfate” will break down when electricity is passed through it and its copper content can then be deposited as a coating on a piece of metal that is sitting in the copper sulfate solution. (Compare ANODISATION.)




ELECTRONICS: The science and profession that deals with the behaviour, control and manipulation of electrons and their flows within solids, liquids and gases. Electronics includes designing, building and repairing electronic equipment. The field of electronics usually refers to the use and manipulation of smaller amounts of electricity, as opposed to the field of “electricity” wherein larger amounts of electrical power are supplied to homes, business buildings, cities, etc.


ELECTRONICS TECHNICIAN, ELECTRONIC TECHNICIAN: A skilled professional who competently deals with electronics. (See ELECTRONICS above.) This as compared with an “Electrician”, who deals with larger volumes of electricity as applied to buildings, structures and general electricity power supply.


ELECTRO-OPTICAL COMPRESSOR: A compressor is an amplifier which decreases volume when the sound signal feeding it has a peak in volume. Compressors have controls on them to adjust how much of a sudden volume peak activates them and how much that peak’s volume is lowered. Some compressors operate using an internal lamp - an actual small light bulb that becomes brighter when the volume of the incoming sound signal becomes louder. The lamp is connected to a circuit that is activated by the changes in its brightness. The circuit responds to how bright the little lamp becomes. The louder the sudden peak of sound entering the compressor, the more the circuit will rapidly reduce the volume of the peak. It is called an “electro-optical compressor” because it works on a combination of the sound’s signal being in an electrical form, together with a lamp which is an optical device, as it deals with light.


ELECTROSTATIC: The electrical force created when friction is applied between two nonconductive materials (e.g. plastic and wool).


ELECTROSTATIC SPEAKER: Speakers and headphones which use a method of producing sound by moving a flat diaphragm suspended in an electrical field.


ELECTROSTATIC HEADPHONE: Headphones that produce sound using electrostatic elements. (See ELECTROSTATIC SPEAKER above.)


ELEMENT(S): 1) All the individual sounds which go into and make up an audio mix. 2) Any physical part of an audio system - an individual loudspeaker in its wood cabinet can be called an element. 3) A term referring to features which a piece of audio electronics may have. “A volume control is one of the elements on a consumer’s CD player.” 4) One of the constituent parts of a video or film, a sound track or musical production.


ELEVATED LEVELS: A non-standard method of audio recording. Some magnetic audio recording tape is advertised to be recorded to at very loud volumes. The tape’s specifications may state that it can accept higher volumes, but all tape has a very specific range of volume it records at best. Still, some engineers record at “elevated levels” and the “trick” of doing so is frequently discussed in mixing magazines and by some recordists and mixing engineers in the industry. There are two reasons why they record with these elevated levels. The first is that doing so can sometimes (not often) make a recorded sound more present or pleasant. The tape “saturates” (can hold no more volume) and starts to “compress” (limit how much loud volume it can accept). This is called “saturating the tape”. It can give the recorded sound a bit of a smoothed character - it can soften the sound and even make it a bit “mushy” sounding. For some music sounds and vocals, engineers will do this on purpose to achieve the effect of saturating the tape. The second reason is because of tape hiss. Tape hiss is the very slight, but audible, “hissing” noise heard when a recorded tape is played back, even when no sounds have been recorded upon it. Dolby Noise Reduction was specifically designed to remove this hiss from recordings. Some engineers who don’t use Dolby noise reduction on their analogue recordings record using “elevated levels” on to tape thinking that if the recorded sound is very loud, one will tend “not to notice” the hiss. The difference in volume between the hiss and the very loud music is so great, they reason, that most consumers will not turn up the volume control of their loudspeakers loud enough to “really hear” the hiss. With this reasoning, they try and get the hissing noise down in volume relative to the loudly recorded music. However, you can still hear the hiss anyway.


ELGAR: Brand name of a line conditioner. (See LINE CONDITIONER.)


ELMO: A brand name of film projector.


ELVIS: Slang term for EVS. Brand name of a digital video and audio hard disc recorder capable of doing fast, real-time switching between any pre-recorded video sources and their respective audio. Used in applications requiring fast, real-time cutting, such as when stills and video clips are accompanying a live speech.


E-MAIL: Written e-mail or E-mail. An abbreviation for electronic mail. The exchange of computer files over a communications network, as on the Internet. One important use of e-mail in addition to text messages is to send a computer file containing a voice recording. These are not of final recording quality, but are often used here at Gold to provide voiceovers for event videos so the edit can be done using the voice of the approved talent prior to the final recording.


EMERGENCY MAN: Trouble-shooter for the technical set-ups prior to and during an event (for audio and video technical).


EM FILMS: See “TECH FILMS” for full list.



EMI: An abbreviation for Electric and Mechanical Instruments. One of the major music companies, founded in 1890. In mid-2001, EMI formed a partnership with Internet providers RealNetworks and RioPort and offers the music of artists on the EMI label.


EMIT TWEETER: A ribbon tweeter made by the Infinity company for many years. “EMIT” is an acronym for Electromagnetic Induction Tweeter.


EMMY AWARDS: The Emmy Awards are issued annually for the best TV shows. Academy Awards are for films, Grammy Awards are for music and Emmy awards are for TV programs. The derivation of the word “Emmy” traces back to a scientific term for the word picture tube - the type used in TVs.


EMPHASIS: This is specifically a digital audio term regarding CDs. Earlier CDs released years ago had their high frequencies raised in volume. The highs were then reduced when the CD was played back by the CD player. Emphasis was used to improve the signal-to-noise ratio of compact disc and other digital recording formats such as DAT when recording. An equal attenuation (reduction) of these frequencies is applied upon playback - this is de-emphasis. A data signal recorded onto the CD tells the playback equipment whether or not to apply de-emphasis. Emphasis is very rarely used in present day CD production. It is, however, still found as a feature on some CD players, as some older CD’s require the setting. (Compare PRE-EMPHASIS and POST-EMPHASIS for data on how this applies to analogue tape recorders.) Technical specifications...Emphasis is applied at a 6 dB/octave level boost to frequencies above 3.5 kHz before A-D conversion. After D-A conversion, a 6 dB/octave level cut is applied, often called de- emphasis.


EMT: A brand of reverberation unit used in mixing studios. They are highly regarded and create very realistic sounding echo for adding to music and voice. This is a German company. No data on what the letters stand for.


EMULATOR: “Emulate” comes from Latin, meaning, “to rival”. An emulator is computer hardware or software which is designed to make one type of computer act as if it were another. In computers and computerised audiovisual equipment, “emulate” means that one computer behaves (operates, acts) in the same way that another does. It imitates the other device. For example, if you were to hook up a digital audio recorder to a digital audio workstation, the workstation computer would need to “emulate” the recorder to a degree, and vice versa, in order for these devices to communicate and be able to pass digital audio information between each other.


EMULSION: One side of all photographic film has a coating of “emulsion”. The emulsion contains the chemicals which create the images on the film when exposed to light or developed in a photo lab or film lab. The word “emulsion” comes from Latin meaning “milk”. (Emulsion looks a bit “milky” when it coats the film.) One can always tell the emulsion coated side of a movie film by placing the film between one’s lips. The sticky side is the emulsion side.




ENCODING, DECODING: In audio and video, encoding refers to a process altering or coding a signal prior to its being recorded or transmitted, with the intention that that encoded signal then be decoded during playback or reception. For example, a stereo audio program can be “encoded” down to just one digital data stream, that stream sent to another location, and a decoder used to restore the stream to the original stereo music for listening. In motion picture sound encoding and decoding are used in Dolby Stereo wherein the Dolby electronics encode four channels of the film’s sound into two. This then gives the ability to put just two tracks of audio on a film print or on a video release of the film. When played back, these two tracks are decoded to play as 4 surround sound channels in a commercial theatre or home theatre. Even the most recent Dolby Digital Surround and DTS equipment do a similar process to get all channels of a film’s surround sound mix onto a DVD-Video disc.


ENCRYPT, ENCRYPTION: The process of coding data so its form is altered requiring that a specific process is used to restore the original data. In broadcast this is used to make transmissions secure from unauthorised reception as is often found on satellite or cable systems.


ENG: Abbreviation for Electronic News Gathering. Term applied to a small portable audio and-or video rig used for gathering news on location. ENG is also the action of recording such news events.


ENGAGE or ENGAGING: The word “engaging” means “tending to attract, charming, pleasing”. Said of an artistic performance of any type that is so. Said of how a loudspeaker system sounds when it produces a natural, pleasant representation of the music, which draws one towards listening interestedly. A mix can have similar qualities.


ENGINE: This is another name for the main computer microprocessor found in computers. It is the main chip that does all the work, such as Intel’s Pentium chips.


ENGINEER: 1) One in charge of a recording session. Also called a Recording Engineer. 2) Often used interchangeably with the word “Mixer” - the skilled professional mixing an audio program live or in a studio. 3) A person with an engineering degree in any technical subject. 4) Any technical specialist in the fields of audiovisual as opposed to actors, musicians, etc.


ENHANCED CD, ENHANCED MUSIC CD: Also called CD-Extra and CD-Plus. A compact disc format which allows the combining of audio recordings and computer data on the same disc, without the possibility of the audio equipment becoming damaged by attempting to play the computer data portions of the disc. “Enhanced” specifically means that the CD has been enhanced by adding text, graphics and pictures. An enhanced CD contains music plus graphics, text and still pictures that go along with the audio program and can be displayed by the consumer on a video screen. Any DVD player’s video output will send the “enhanced” portion of the CD to a TV screen. There are some models of CD player that also have video outputs that will send text, graphics and pictures to a TV. One such player is the Sony model CDBCX450 CD player.


ENHANCED DEFINITION TELEVISION (EDTV): Another name for a type of High Definition TV broadcasting. (See HIGH DEFINITION TELEVISION for more information.)




ENHANCED PC: The expansion and enhancement of personal computer services and power so as to enable it to control everything from radios, TVs, the Internet and even picture frames (wherein picture graphics can be digitally changed as desired).




ENTRY LEVEL: The quality level of better home consumer audiovisual equipment yet this level of equipment is of the lowest quality of its type - but allows one to “enter” the realm of higher quality audiovisual playback. The better quality audio equipment sold at Circuit City could be said to be “entry level” high fidelity “audiophile” level gear.




ENVELOPMENTAL SOUND: The sound that naturally builds up and decays inside a room or performance hall. When a sound is played in a room, its reflections very briefly build up and then die out. The sound heard in a room or hall, when there is music or another audio source, is made up of the direct source of the sound (directly from the instrument on the stage, for example) and additionally all the many various reflections and delays of that direct sound as it goes out into the room reflecting off all surfaces (walls, ceiling, etc.) All combined, these many different aspects of the sound are called the room’s “envelopmental sound”. It usually refers to all these elements heard at their loudest peaks.


EP: Extended Play. The slowest (and lowest quality) recording time setting for a consumer’s video deck. A standard one hour video cassette will record and play two hours of program.


EPG: Short for Electronic Programming Guide. This is the “TV guide” many consumers receive over their home entertainment system television. It is received via modem or similar connection. It tells the consumer all the TV programs playing and when. Usually one pays to receive this service. It looks similar to the TV guides that come on-screen when you are watching satellite or cable TV but covers all TV programming in your area.


EPROM: Erasable Programmable Read Only Memory. This is a small computer chip that can be erased and new data stored. It is erased by shining ultraviolet light on the chip.


EQ, EQ'ING: Short for “equalisation” or “equaliser”. The term “equalisation” comes from the technician’s definition of equalisation, which is making all frequencies equal in volume.


EQ CURVE: See EQ. An EQ curve is a line that could be graphed showing the sound frequencies of a given sound, from the low bass to the high treble. One that has a lot of high treble information could be said to have a rising curve - or a high EQ curve - or a steep treble curve. A loss of bass frequencies would be said to have a dip in the curve in the low bass. It is a curve up or down which represents the character of the sound in terms of more or less of certain frequencies.


EQUALISATION: The term equalisation may be somewhat misleading since, like alignment, it seems to imply some sort of necessary adjustment process to bring an audio signal within published specifications. Some equalisation is done for this reason. For example frequency adjustments are made to overcome the limitations of the recording medium; however these adjustments, when correctly made, should have no apparent effect on the program as heard by the listener. On the other hand, equalisation may be a form of signal processing when the adjustments are made to modify noticeably the frequency response of the signal being treated. Here, there is no intention to conform to a standard. Changes are made according to the taste of the engineer or producer. The signal is equalised to suit the standards of the moment and these may change the next moment, according to the taste of the listener.


EQUALISER: A piece of audio mixing equipment used in equalisation.


EQUIPMENT RACK: A cabinet with metal rails that have holes to accept screws that hold equipment in the rack.


EQUIVALENT FRONT, EQUIVALENT REAR (loudspeaker): Said when mixing music or film sound in surround sound. If one is mixing a sound in the right front channel loudspeaker of a surround sound mix, then the “equivalent rear” is the rear loudspeaker on that same side behind oneself (the right rear loudspeaker.) If one is mixing a sound heard in the left rear loudspeaker, the “equivalent front” is the front left loudspeaker. It is a term used due to the fact that often a Mixer, when mixing in surround sound, deals with pairs of speakers - the back left and front left, the back right and front right, the front right and front left, the back left and back right. Each individual loudspeaker therefore has its “equivalent” on the opposite side.


ERASE CURRENT: A stream of high-frequency electricity sent to the erase head of a tape recorder to erase any recording previously made on the recording tape. The current activates wire coils inside the head that then causes a magnetic flow that erases the tape.


ERASE HEAD: A separate head, situated to the left of the record and playback heads on an analogue audio tape recorder, that removes previously recorded signals from a tape as it passes across. The erase head also functions to prepare the tape to receive a new recording.




ERROR CORRECTION: Also known as “error concealment”. Putting bits (computer data) into a digital audio signal to replace lost bits where the digital recording or processing system cannot verify whether the lost bits were 1’s or 0’s (“on” or “off”) but can make a good guess by comparing other known bits which are close in position to the lost bits.


ERSATZ SOUND FIELDS: “Ersatz” means “artificial.” Some consumer home theatre audio equipment has internal electronics designed to create ersatz sound qualities, such as making music or a film sound as if it is being played in a large auditorium. The equipment has the ability to create, artificially, the “sound field” of the auditorium. It might have the ability to play music as if it were in the sound field of a “jazz club”. Such equipment has settings and adjustments which enable this to be done. They create “ersatz sound fields”.


ESP: (Electronic Shock Protection). On portable CD players with this feature internal digital circuitry stores several seconds of audio in memory. If the laser skips during playback, this stored memory allows the audio to continue uninterrupted until the laser regains the correct position. This type of storage of the music actually degrades the quality of the audio, not particularly noticeable when one is jogging, but nonetheless, most good portable CD players have a switch to bypass the feature.


ETCHED: Said in describing sound: Having strong high treble frequency information and is therefore very clearly heard to almost an excessive degree. When listening to music, an “etched” sound seems very sharply outlined as to its location relative to other instruments. Very clear, but verging on being unpleasant to hear. Emphasis in high frequencies around 10 kHz or higher.


ETHERNET: “Ethernet” is a system developed by the Xerox Corporation used for connecting computers, printers, workstations, terminals, etc. Ethernet is a standard that is essentially composed of an electronic circuit installed in a computer terminal, and wiring that connects the terminal to a central computer and-or other terminals. Ethernet works like a telephone party line, so anyone can transmit data as long as no other device is transmitting. The more users, the slower the network because devices can't all "talk" (send data) at the same time. However, more recent and advanced systems have increased Ethernet’s capacity for transmission. Ethernet operates at speeds of up to 10 megabytes/sec (Mbps) or more - recent versions are faster. It uses a network interface card that functions between the computer and the network cabling and transmits and-or receives the computer data in the form of radio frequency signals.


“E TO E” or E TO E MONITORING: Stands for Electronics to Electronics. When one is recording sound, either live such as on a movie set or simply making a copy from one machine to another, there are two basic ways one can listen to the audio. One is when you switch your preamplifier to “input” or “source”. In the “input” or “source” position, one is hearing the sound before it goes onto the tape of the recording machine (or the computer’s memory storage in the case of computerised recording equipment). In such a case one is listening only to the electronics at the input of the recording machine, not the actual tape. This is called “E to E” or “E to E monitoring”. The other is switching the preamp to “tape”. When the switch is set to “tape”, you are hearing the sound off of the tape that has just been recorded onto. In this case you are not listening E to E, you are listening to the sound from the tape. In this way you can be sure that the sound actually was recorded onto the tape. If you listen only E to E, you will hear the sound before it hits the tape and won’t be sure the sound actually was recorded. (Of course, if the tape recorder is stopped, the only way you’ll hear any sound at all is if you set the switch to “input” and listen E to E.) The Recordist or Copyist usually switches back and forth between “input” (E to E) and “tape” during a recording to get a comparison between the sound coming into the recorder and the sound that has been recorded onto tape by the recorder. Note that this is not the same thing as A-Bing a recorder.


eTV: “eTV” is an abbreviation for Intel’s enhanced Television, a form of interactive digital TV service. The eTV system allows viewers to interact with the TV programming in many different ways. (It requires that TV stations provide a signal compatible with the Internet.) eTV also enables a computer user to have the TV screen split into two concurrent images, one half showing the TV broadcast and the other displaying his or her computer screen. This would allow one to watch TV and interact with it using a personal computer, or simply be doing work on the computer but still able to see both the TV broadcast and the computer display on the same video screen.


EUPHONIC: Pleasing to the ear. The word comes from “euphony” which literally means “agreeableness of sound; pleasing effect on the ear” - from “phon”, meaning “a sound”.


EUPHONIX, EUPHONIX MIXBOARD, EUPHONIX DESK: Name brand of high quality professional studio mixing consoles (mixboards). Euphonix consoles have a computerised control board, which the Mixer operates in the studio, but the actual electronics which process the sounds are located in another room in a tall cabinet of electronic circuit boards, one for each mixboard channel.





1) In computers, any action the computer does for any duration.

2) The number assigned by a computerised editing system to each performed edit.

3) A show or performance.

4) Any specific action caused by the computerised control of a machine or device.


EVENT-BASED AUDIO: In computer audio (Internet, etc.), “Event-Based Audio” is a format requiring that the entire audio file be downloaded and-or the file opened before it can be played back. This is as opposed to “streaming”, which allows one to hear audio over the Internet or computer system in real time without first downloading the entire program.


EVENTIDE: Name of a company which manufactures digital delays and other audio mixing equipment.


EVENT RIG (Event Broadcast Rig, Event Recording Rig): These are Gold production lines which are brought to each major event to record and mix the show’s audio. The broadcast rig is set up inside the truck. It has all the mixing equipment and facilities to do the job. The record rig is usually set up behind the curtains off to the side of the stage. It records the main microphone, all audience microphones, etc. with high quality digital recorders and electronics.




EXABYTE, EXABYTE TAPE: A brand name and format of digital audio tape and tape recording system which can store up to 5 Gigabytes of program, or about 5 hours of uncompressed audio. The Exabyte tape looks like a miniature ½ inch videocassette. Exabyte tape is often used with Digital Audio Workstations to record an audio program off of the hard drive so it can be stored, and used at a later time - thus freeing up the computer’s hard drive for other audio programs. It is also used as a master tape in the first step in CD manufacturing. (The audio program is recorded onto an Exabyte tape with all the data needed to create the master disc used in CD replication.) Exabyte is a self-correcting data medium. It checks all data as it is being recorded (“written”) and re-writes it as necessary, removing errors from the data.


EXCITER LAMP: A small lamp inside a film projector that shines its light through a very specific area on the edge of the film in order to read an optical sound track on films so equipped. On the edge, printed into the film, are thousands of very small black lines which perform a similar function to recording tape - they are the soundtrack. As the black lines pass in front of the lamp, because they vary in size, they cause a constantly changing shadow to be cast onto a “reader” (a pick-up device called an “optical sound head”). The pick-up is able to convert the light changes into an electrical signal which is then further processed into audible sound which is heard out in the theatre. The lamp is called an “exciter lamp” because it “excites” (activates) the entire process. Because the process involves the use of light (optics), the pickup is called an optical sound head. It does the same basic job as a magnetic head on a tape player, only using light. This optical sound process has been in use for many years in the film industry, and is superseded by the various digital audio theatre surround sound formats and brands such as Dolby and THX.


EXCITERS (OR ENHANCERS): A term referring to any of the popular audio (mixing) special-effects signal processing units used primarily in recording and performing live. All exciters work by adding a small amount harmonic distortion of some sort - but harmonic distortion found pleasing by most listeners. Some of these units also increase high frequencies (treble) information to make the mix or sound from the stage stand out.


EXCURSION: In this usage the word “excursion” means the extent of the range of motion of any moving part. It describes the motion of a loudspeaker which is reproducing sound. “Excursion” is the total distance a loudspeaker can move forward and backward in relationship to its resting position. When a loudspeaker receives electrical impulses from an amplifier it goes into motion back and forth. The amount of excursion depends on the strength of the electrical impulses. Bass sounds produce the largest impulses and these make a loudspeaker move the most. Loudspeakers are designed to be capable of certain limits of excursion. They can distort or even be damaged if these limits are exceeded. This could happen if the amplifier being used is too powerful for the loudspeaker or if a sudden uncontrolled peak in volume occurs.


EXTENDED SURROUND: (Abbreviated ES) This is a name given by DTS (Digital Theatre Systems) to describe a feature of their surround sound systems for both commercial and home theatres. The feature includes the use of a DTS “Surround Back Channel”. DTS claims it provides “true discrete operation” in the surround loudspeakers - meaning that the surround speakers have their own entirely separate (discrete) channel and the system then provides “360 degrees of surround reproduction”. This “extends” the effect, and thus the name of the feature, ”Extended Surround”. Similar to Dolby Surround Extended (EX) - which is basically the same thing.


EXTENDED (HIGHS AND BASS): When an audio system produces both the very lowest bass notes and the very highest high notes with ease and clarity, it is said to sound “extended”. Any audio equipment or a mix or recording which has this capability or attribute is said to have “extended bass response” or “extended highs”.




EXTENSION: The usable outer limits of an audio component's frequency range (the lowest bass and highest treble). Includes loudspeakers.


EXTERNAL AMPLIFIER: Any audio amplifier which is not built into a speaker cabinet. The amplifier is “external” to the speaker. Some speakers do have amplifiers built in, and volume controls right on their cabinetry.


EXTERNAL CONVERTER: A digital to analogue or analogue to digital converter that is contained in a separate box, not in the CD player, DVD player, etc.


EXTERNAL CROSSOVER: A crossover is an electronic circuit used to divide an audio signal into two or more separate frequency bands (ranges of frequencies) as it travels enroute to loudspeakers. This is done because different types and sizes of loudspeakers are designed to specialise in handling different ranges of frequencies. A crossover routes the correct range of frequencies to the loudspeakers designed to properly handle them. Some crossovers are built into the speaker cabinet. These are called “internal crossovers”. When the crossover is in a separate box outside (external from) the cabinet, the crossover is said to be an “external crossover”. A loudspeaker system consists of the individual speaker drivers, the crossover and cabinet with connectors to receive audio signal. A speaker system can include many different speakers in many different cabinets all of which are provided audio signal via one or more crossovers.


EXTERNAL INPUTS: The connector points on professional level audio or video equipment which allow one to plug in other devices which can then be used to manipulate or affect the sound or video already playing. For example, an electric guitar amplifier always has an input which allows one to plug in the guitar. However, many such amps also have “external inputs” which allow other devices to be plugged in to alter the guitar’s sound. Such inputs are usually on the back of the amp. Mixboards have external inputs which allow other audio mixing devices to be hooked up to them to help mix and process the sounds. These inputs are not the main inputs through which the sounds themselves arrive to the mixboard.


EXTERNAL POWER SUPPLY: When a power supply is housed inside audio equipment it can add noise to the sound signal. An effective way of handling this is to build the power supply as a separate unit housed in its own box. This is called an “external power supply”. The external power supply is placed away from the audio gear where alternating current (AC) noise won’t interfere with the sound. It receives AC power and sends out DC power to the electronic circuits in the equipment (which usually run on DC power). DC power doesn’t vibrate back and forth like AC does, so it doesn’t create noise in a circuit.


EXTRACTION: This is the name given to a digital audio process for film sound which takes mono or stereo mixes done for older films or music releases (any which were not originally mixed in surround sound) and synthesises a surround mix that can then play in theatres and homes with surround sound systems. The Extraction process was developed by Hank Waring, a noted professional in the audio industry.


EXTREME HIGHS: The range of audible frequencies above 10 kHz.