Glossary

AB Stereo Often used to distinguish MS stereo from the convention signal using left and right signals. In the context of microphones it often implies the use of spaced omnidirectional mics rather than a coincident pair.

ADATA digital multitrack recording system that gives eight tracks on an S-VHS videocassette.

ADPCM (Adaptive Differential Pulse Code Modulation)Conventional Pulse Code Modulation stores the values of a waveform as a series of absolute values. Differential PCM does not do this but, instead, sends the data as a series of numbers indicating the difference between successive samples.

ADSL (Asymmetric Digital Subscriber Line)Sometimes known as a ‘cable modem’ which is telephone data service where higher data speeds are available. The connection is permanently open. The ‘asymmetric’ refers to the fact that the data rate is slower for uploads compared with downloads. The actual data bandwidth that is available is shared between a number of subscribers (contention ratio) and will varying depending on how many are sending or receiving data at any moment.

AES (Audio Engineering Society)Among other things, the AES lays down technical standards. In the context of this book they are best known for a professional standard for conveying digital audio from machine to machine which has also been adopted by the EBU.

AES/EBUA professional digital audio standard for transferring digital audio between machines. This is balanced and uses XLR connectors. The data format is similar but not identical to S/PDIF which can see an incoming AES/EBU format signal as copy prohibited.

AIFFApple AIFF (.AIF, .SND) is Apple's standard wave file format and is a good choice for PC/Mac cross-platform compatibility.

ALC (Automatic Level Control)See AVC.

AliasingSpurious extra frequencies generated as a result of the original audio beating with a frequency generated within the audio processing system (usually the sampling frequency in a digital system). Filters are used on the input to prevent this but these filters themselves can produce degradation of the signal unless very well designed.

Analog AudioUntil digital techniques came along audio was conveyed and recorded by using a property that changes ‘analogously’ to the sound pressure. This property might be electrical voltage, magnetization or how a groove wiggled. Digital audio replaces this by a series of numbers.

AV (Audio Visual)AV standard hard drives are able to cope with long runs of data, such as a long continuous audio recording, without stopping to recalibrate themselves for temperature variations.

AVC (Automatic Volume Control)Often found as an option on portable recorders. This automatically adjusts the recording level from second to second. This can cause trouble when editing as the background noise will be going up and down. However, modern AVCs work surprisingly well. The background matching becomes a trivial problem when editing with a PC digital audio editor.

BalancedNormal domestic audio connections are unbalanced; a single wire carries the audio which is surrounded by a screening braid connected to earth as the return circuit. These circuits are prone to pickup of unwanted signals as well as high frequency loss when used beyond about 5 metres. Balanced circuits use two wires to carry the audio (still within a screening braid). The audio in the wires is going in opposite directions, as one wire goes positive the other goes negative. Interfering signals induce in the same direction on both wires. The input circuit is designed only to be sensitive to the difference in voltage between the two wires and therefore ignore the induced interference.

Barrier micsBarrier mics are designed to be placed on large flat surfaces rather than suspended in free air. These are often referred to as PZMs (Pressure Zone Microphones) after a commercial version.

belSee Decibel.

BinauralCurrent practice is to use this term to mean two channel audio balances intended to be heard on headphones.

BIT (Binary digiT)Digital/PCM systems use pulses which indicate either an ‘ON’ or ‘OFF’ state. Each individual piece of data is known as a bit.

BNCA professional video/digital audio connector with a locking collar.

ByteA group of 8 bits (allegedly a contraction of ‘By Eight’). This is the standard measure of the capacity of digital systems.

CapacitorAn electrical component that can store electrical charge, formerly known as a condenser. They consist of two parallel ‘plates' separated by an insulator. The plates are so close together that when they are charged the positive charge on one plate is attracted to the negative charge on the other. The closer they are together, the greater the attraction. This increases the amount of charge that the device can store. A practical capacitor's plates are in fact metal foil sheets separated by a sheet of thin insulator rolled into a cylinder, rather like a Swiss roll. This reduces their size and gives them a cylindrical appearance. A specially constructed capacitor forms the basis of electrostatic microphones.

Cardioid (heart shaped)The most common of microphone directivity shapes (see Page 189).

CD (Compact Disc)When used without qualification this is taken to mean a standard audio CD. Subsequently adopted for data use in computers, this has led to many variants (see below).

CDR (Compact Disc Recordable)A recordable CD which cannot be erased.

CD-ROM (Compact Disc Read Only Memory)A CD containing data rather than audio.

CD-RW (Compact Disc Read-Write)A recordable CD that can be erased. While they can be recorded in audio format, most domestic CD players cannot play them.

Chequer boardingA technique for mixing sections of audio or video (see Page 71).

Cinch plugAnother name for phono plug.

ClockAll digital systems have a reference clock which acts rather like the conductor of an orchestra to keep everything in sync (see Appendix 1).

CloneIn the digital audio context this is used to mean making an exact sample for sample copy. This is not possible with systems like Minidisc, which use lossy compression systems.

Coax, Coaxial plugA generic term for a connection that uses a cable where one or more conductors are surrounded by a wire braid that helps screen out interference. In the UK, this term is most often used for the plug used for television aerials. In the audio context, some companies use this term for a phono plug.

Coincident pairA stereo microphone technique using directional mics placed as close together as possible.

Compact CassetteThe proper name for the ordinary analog audio cassette; undoubtedly the most commercially successful audio recording medium ever invented.

Compression, audioCompressor limiters are the most used effects devices in the studio. They can be thought of as ‘electronic faders' which are controlled by the level of the audio at their input (see Page 90).

Compression, dataThere are two types of data compression. Non-Lossy: The first, and traditional, form of compression reduces the data to be stored on a disk or sent via a modem. The best known format is the Zip format. A Zip file can be uncompressed to recreate the original data without any change or error. Lossy: Graphics and audio are often compressed using formats that approximate the data using assumptions about how we see and hear (see Page 154).

Condenser MicrophoneCondenser is an old term for capacitor.

Cool Edit ProA commercial audio editing package for Windows, combining both linear and non-linear editing. This was bought by Adobe and transformed into Audition.

DACsee Digital-to-analog converter.

DAO (Disc At Once)A technique of burning a CD in one go. This has a number of technical advantages, notably giving the ability to control inter-track gaps or even recording audio into those gaps.

DAT (Digital Audio Tape)Originally a generic term for ‘Digital Audio Tape Recorder’. This is now used specifically for a format developed by Sony, supported by scores of other manufacturers, that has become popular amongst professionals and semi-professionals alike for mastering digital audio. This is now becoming obsolete.

DataPlural of 'datum’. From Latin 'things given’. The word is often erroneously used as a singular, that is ‘The data are’ not ‘The data is’.

DAW (Digital Audio Workstation)A dedicated computer audio editor with specialized controls and software.

dBDecibel.

dBADecibels are used widely in the field of acoustics, audio and video. Subtly different scales are used and the different types of decibel are indicated by a suffix. The dBA is used in the field of acoustic measurement.

dbxA commercial company that is best known for developing a popular analog noise reduction system.

DC OffsetPoor analog to digital converters can have a DC offset that ‘pushes' the audio away from being centred around zero volts towards either the positive or negative. This is a major cause of clicks on edits (see Chapter 4.2,Figure 4.9).

DecibelOne-tenth of a bel. The normal way of measuring audio. It is a logarithmic system using a standard reference level. Values are expressed as a ratio of a standard level. The bel itself is too large a unit to be convenient for audio. The Richter units used for measuring earthquakes are identical to bels but with a rather louder reference level! (see Page 6).

Delta modulationA technique where the difference between samples is sent instead of the absolute values usually sent by PCM.

Digital audioSound pressure level variations are represented by a stream of numbers represented by pulses.

Digital audio workstationA dedicated computer audio editor with specialized controls and software.

Digital Versatile Disc (DVD)The successor to the compact disc. It uses similar technology but takes advantage of technical developments since the CD was introduced. Recordings are made at a much higher density, eight times greater than CD. Additionally the DVD can not only be double sided but also each side can be made up of two layers. This gives massive data capacity, enough for full-length films with 5.1 channel audio. The ‘0.1’ is a, not very good, engineering joke. There are, in fact, six channels of audio but the sixth channel is a low bandwidth one used for low-frequency effects.

DIN (Deutsche Industrie-Norm)German industrial standard. This includes the audio/MIDI/computer DIN plug. A standard sized case and connector containing a number of pins. The most common type met in the audio and MIDI context is the 5-pin 180°.

Disc, DiskA convention has grown up where disc-based media using a magnetic medium are spelt as ‘disk’ (with a ‘k’). Optical recordings like CD and Minidisc, as well as gramophone records, remain spelt as ‘disc’ (with a ‘c’).

DitherA low-level signal, usually random noise, which is added to the analog signal before conversion to digital. Its effect is to reduce the distortion caused by quantization.

DolbyDr Ray Milton Dolby is possibly the most influential individual in audio. His company, Dolby Laboratories, began by making audio noise reduction systems. The first, a professional system, became known as Dolby A-type. A simplified system, called Dolby B-type, revolutionized the compact cassette medium for consumers. Dolby C-type gives about 20 dB noise reduction compared with the B-type system's 10 dB, albeit at the cost of poorer compatibility when played on machines without decoding. Dolby SR (Spectral Recording) is an enhanced professional system that can give better than 16-bit digital performance from analog tape. Dolby S is a powerful compact cassette system based on a simplified version of SR. As other companies have to obtain a Dolby trademark, the company has become the effective setter of standards for cassette machines, as minimum audio performance is set by Dolby Laboratories to allow their systems to be used.

Dolby DigitalStarted in the cinema industry, this is the digital multi-channel sound format most widely used on DVD and with digital television.

Dolby StereoDolby Laboratories devised a system for putting stereo onto optical release prints in the cinema. This was combined with a phase coding system that allows surround information to be heard. The Left total and Right total channels can be decoded to give Left, Centre, Right and Rear loudspeaker information. In the early 1990s the term ‘Stereo’ was dropped, and the analog film format is now simply referred to as ‘Dolby’.

Dolby SurroundThe domestic version of Dolby Stereo as found on video cassettes, CDs, TV broadcasts and video games.

Drop inSwitching from play to record while running to make an electronic edit.

Drop out(1) A momentary loss of sensitivity in an analog recording medium. Digital systems can correct or conceal errors resulting from drop outs in the medium. However, if they fail you will hear a mute instead. (2) Switching from record to playback to end a drop-in.

DTMF (Dual Tone Multi-Frequency)These are the tones that modern phones make when dialling. They are used to code the digits 0-9 as well as the special system codes of ‘*’ and ‘#’. Four extra codes are also available known as ‘A’, ‘B’, ‘C’ and ‘D’. The sixteen possible combinations are achieved by sending two frequencies (hence ‘dual tone’) out of a possible selection of a total of eight.

DVDSee Digital Versatile Disc.

Dynamic microphoneAn alternative word for a moving coil microphone.

Dynamic rangeIn audio systems the dynamic range available is determined by the number of bits used to measure each sample. In theory for every bit extra another 6 dB of signal-to-noise ratio is gained.

EBU (European Broadcasting Union)A trade association for European broadcasters, which also sets technical standards.

EchoAlthough this is often used interchangeably with the term reverberation (or ‘reverb’), they are technically different. Echo is where you can distinguish individual reflections (echo ... echo ... echo) while reverberation is where there are so many reflections that they merge into one continuous sound (see Page 99).

Edit Decision List (EDL)Used in a non-linear editing process where the audio files are not altered. Instead a list of instructions (the Edit Decision List) as to what section to play when, at what level, etc. is created which causes the hard disk to skip around and produce apparently continuous audio.

EDLSee Edit Decision List.

EIDE (Enhanced Integrated Drive Electronics)The most widely used (and hence cheapest) form of hard drive. Most PC motherboards are equipped to handle four drives. The usual alternative is SCSI but see also SATA.

ElectretA form of capacitor which remains charged permanently. This means that when constructed as a microphone, it does not need a polarizing voltage. Typically a simple 1.5 VAA battery is used to power the built-in amplifier.

ElectromagneticDevices where magnetism is used to create electricity or electricity is used to create magnetism. Within audio, a moving coil (dynamic) mic is used to create electricity (the audio signal) by the diaphragm pushing and pulling a coil of wire between the poles of a magnet.

ElectrostaticElectrostatic microphones use a diaphragm that is one of the plates of a capacitor held charged by a polarizing voltage (see Page 192).

EQPronounced ‘Eee’ ‘Cue’. A widely used abbreviation for ‘equalizer’, a term for devices like tone controls which modify the frequency response of an audio system. Such devices were originally used by engineers actually to equalize, or correct audio deficiencies in land lines and recording systems. They were then borrowed by studio operators to improve their recording mix. Nowadays equalizers are designed specifically for studio use.

Error concealmentA technique where errors can be detected but not corrected. Instead they are concealed often by replacing the sample with an average of the samples either side. This is called interpolation (see below).

Error correctionAs digital audio is a series of numbers, extra numbers can be added having been generated by various mathematical means. At the receiving end these numbers can be generated again from the incoming data. If they are different from the extra numbers sent, then error has been detected. With suitable maths, the errors can often be corrected. As the binary nature of the signal represents only ‘0’ or ‘1’, it is clear that, if the incoming value is established as being wrong, then the correct value must be the only other value. Interpolation-, is a technique where when an error is detected a value between the preceding and following value is substituted, whereas full error correction actually reconstitutes the data. Interleaving- Errors can be made easier to correct by interleaving the data so that they are physically spread out on the medium so that a single drop out in the medium does not produce a single burst of errors.

fff ‘ f is a music term for loud (Italian- forte); the degree of loudness is indicated by the number of ‘f's, thus fff is very loud.

FFT (Fast Fourier Transform)A mathematical way of defining a filter.

Figure of eightTerm used to describe a microphone that is sensitive front and back but dead at the sides.

FirewireA standard way of connecting apparatus to a computer that is supported by both PCs and Apple Mac computers. The devices are 'daisy-chained’ together and can be connected or disconnected without having to reboot the computer. This is faster, although presently less common, than USB.

FlangingPhasing with continuously varying delay.

FlutterRapid variation of pitch, often caused by a dirty or damaged capstan pulley on an analog tape machine. A digital recording will be free from this fault.

Flutter echoTerm used by those of us who tend to use the terms ‘echo’ and 'reverb’ interchangeably to show that we are really talking about echo.

FM (Frequency Modulation)A way of sending data, or audio, using a carrier frequency which is varied in pitch. This is used by FM Radio, VHS video cassette, Hi-Fi sound, many hard disks, etc.

FXA widely used abbreviation for ‘effects’.

GainAnother word for amplification.

Giga1000 million, hence 1 gigahertz = 1 000 000 000 hertz = 1 GHz.

GlitchA discontinuity in sound, due to data errors.

Gun micA generic term for very directional mics using a long tube and phase-cancellation techniques. Also known as shotgun or rifle mics. As they are very sensitive to wind noise they are usually concealed in long furry sausage-like windshields.

HexadecimalA numbering system based on the number 16 instead of 10. The characters 0-9 and A-F are used:

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10, 11, 12 etc.

It is a convenient notation for binary numbers as used by computers and for MIDI. FD is easier for a person to distinguish from FB than 11111101 from 11111011.

HypercardioidA microphone which has a slightly narrower front pick up compared with a cardioid. The penalty is that there is a reduced sensitivity lobe at the back, giving a dead angle a few degrees to the side of this.

IDE (Integrated Drive Electronics)A way of connecting hard drives to personal computers. It is very cheap and has become very popular and hence become even cheaper. Although the technology has much improved it is regarded, by many, as inferior to SCSI as it uses the computer's processor and slows down programs that are being run at the time. It has been said that IDE works in a way analogous to arriving at a shop counter and asking for an item and saying ‘I'll wait’ whereas SCSI allows you to go away and do something else because it will 'deliver’. See also SATA.

ImageThe perceived location of a single source within the sound stage. The image may be narrow (panned mono) or wide (string section). It may be precise or blurred.

InterleavingError correction technique (see under Error correction above).

InterpolationError concealment technique (see under Error correction above).

ipsInches per second.

ISDN (Integrated Services Digital Network)Sometimes ironically referred to as the ‘It Sometimes Doesn't Network’, which gives you a direct digital connection to the phone net-work. There are various audio coders that allow good quality down, what is effectively, a telephone line. Different organizations have standardized on different systems and some manufacturer's gear is not fully compatible.

Kilo (K)The word kilo when used in the context of digital systems usually means 1024 not 1000. This represents the maximum value of a 10-bit word (i.e. 2 to the power of 10). This is not cussedness, but is used because it represents a very convenient unit. So the term 64K will mean 65 536. Some publications use the abbreviation ‘K’ to mean 1024 and ‘k’ to mean 1000.

LimitingCompression of greater than 10 – 1.

Line inAn input to be fed by amplified audio rather than a microphone.

Line levelDomestic outputs tend to be -8dB with professional outputs being +4dB; 0dB is 0.775 volts. This strange value dates from telephone technology, where 0.775 volts gave 1 milliwatt into a 600 ohm circuit.

Line outAmplified output of a device.

Linear editorAn editor where the audio files themselves are altered by the editing process.

Lossy/non-LossySee Compression, data.

LP (Long Play)Usually used to refer to 12 inch gramophone records. However video cassettes, DAT and Minidiscs have a long play mode.

MasteringThe general term for transferring studio material to a final stereo 'master’ which will be used to generate the copies sold to the public.

MegaOne million, hence 1 megahertz = 1 000 000 hertz = 1 MHz (note upper case ‘M’; lower case 'm’ means milli = 1/1000th when used as a prefix).

MicPreferred British abbreviation of the word microphone.

MicroOne-millionth, hence one microsecond (1 ^s). Used colloquially to mean small computer.

MIDI (Musical Instrument Digital Interface)A standard system for communicating performance information between synthesizers and computers.

MilliOne thousandth, hence 1 millimetre = 1 thousandth of a metre (1 mm).

MonauralSometimes used to mean monophonic but really means listening with one ear!

Monitoring speakerMonitoring speakers are designed to be analytical and reveal blemishes so that they can be corrected. As a generalization, Hi-Fi loudspeakers make the best of what is available.

MonoContraction of monophonic; also contraction of monochrome (i.e. black and white pictures).

MonophonicUsually contracted to ‘mono’, this is conventionally derived from the stereo signal by a simple mix of left and right channels. Beware of some portable tape machines which have a switch labelled mono. This often means that only one input is fed to both legs of the recording not that the two inputs are mixed and fed to both legs. It is very easy to end up with an interview tape that only has questions on it if a reporter is not aware of this.

Moving coilThe most common type of microphone and loudspeaker. A coil of wire attached to a diaphragm is suspended in a magnetic field. If the coil is moved by pressure on the diaphragm a small voltage is generated. If a current is passed through the coil, the diaphragm will be moved.

MPEG (Motion Picture Experts Group)MPEG is a series of Lossy compression systems for audio and video.

MS (Middle Side)A stereo technique where instead of the left and right information being used for the two audio channels, the middle and side are used. The middle signal corresponds to the mono signal. The side signal corresponds to the amount of 'stereoness’. It is zero for centre signals and at a maximum for sounds coming from the extreme left or right.

MultiplexGenerally any method of carrying several signals (e.g. stereo left and right) on a common circuit. Digital radio and television are broadcast using multiplexes that carry a number of channels; how many depends on the quality required.

NanoOne-thousand-millionth, hence one nanosecond (1 ns).

NICAM (Near Instantaneously Companded Audio Multiplex)Digital system used in the UK to add stereo sound to television broadcasts.

Noise reductionAnalog recordings are often made using noise reductions systems like Dolby and dbx. They boost the signal on record and apply a correction to this on playback. In the process noise and hiss are correspondingly reduced. In the digital editor context noise reduction usually refers to various software solutions that remove clicks, hiss or noise from an existing recording, usually a transfer from an analog original.

Non-linear editorAn editor which does not alter the original audio files. Instead it uses some form of edit decision list to instruct the computer to jump around the hard disk reproducing and mixing audio as required.

NTSC (National Television System Committee)American color television system.

Nyquist limitThis is named after Harry Nyquist the Bell Telephone Laboratories' theoretician who first enunciated the principle that you have to sample at a frequency at least twice that of the highest you intend to transmit.

OmnidirectionalOmnidirectional microphones are equally sensitive to audio from any direction.

Out-of-phaseIf loudspeakers are out-of-phase, this means that their diaphragms, instead of moving in and out together, move in opposite directions. This has the effect of blurring the sound image and reducing the bass response of a system.

PAL (Phase Alternate Line)Color television system used by most countries in Europe. This is often used to imply a 25fps frame rate, although 30fps versions do exist. Many videocassette machines will output a PAL signal at 30fps when playing an NTSC tape.

PATA (Parallel ATA)Used to distinguish the original IDE (Integrated Drive Electronics) bus; also known as the ATA(Advanced Technology Attachment) specification (ATA Bus). The IDE bus is a Parallel bus. A new form is being introduced called Serial ATA (SATA), as a result the parallel form is now commonly called parallel ATA (PATA).

PCOriginally a generic term for ‘personal computer’ this has been hijacked to mean a computer based on the original IBM design. While sometimes used to imply using a Microsoft operating system such as Windows, as opposed to Apple Mac, they can also be used for other operating systems such as BeOS, Unix, Linux, etc.

PCM (Pulse Code Modulation)The technique of sending numbers as a series of pulses.

Phantom voltsElectrostatic (capacitor or condenser) mics need to be powered to work. Balanced studio mics are often powered by adding the DC voltage (usually 48 volts) to the audio wires. Circuitry at each end separates the audio. Although the circuit behaves as if there is an extra wire for the power, it has no physical existence, hence the term phantom.

PhaseA measure of the relative delay between two waveforms at the one cycle level. The positive-going zero crossing is described as 0° and the negative-going zero crossing as 180°. Where the difference between the two waveforms is exactly reverse – positive in one is matched by negative in the other – they are said to be 180° out-of-phase, or just out- of-phase.

PhasingThis is caused by selective cancellation of some frequencies either using a comb filter or, more often, by mixing two nominally identical signals with a short delay between them. In the late 1960s this was a much loved ‘psychedelic’ sound. If the delay is continuously varied this is called flanging.

Phono plugThe RCA phono plug was originally designed to connect phonograph (gramophone) turntables to amplifiers. This has become a universal way of connecting unbalanced audio (and, often, video) largely because of the cheapness of the connector.

POTS (Plain Old Telephone System)A general term for ordinary phone lines which have limited capabilities compared with specialized systems using newer technology such as ISDN.

ppp ‘ p’ is a music term for quiet (Italian- piano); the degree of quietness is indicated by the number of ‘p's, thus ppp is very quiet.

Pre-emphasisA technique of boosting high frequencies on record or transmission; they are then restored on playback or reception. In the process any added hiss has top cut applied to it.

Program, programmeIn this book ‘program’ is used in the context of computers. The British spelling is used in the context of radio and TV programmes.

PZM (Pressure Zone Mic)See Barrier mics.

Quantizing(1) The process of turning an analog signal, like audio, into numbers. (2) In MIDI sequencers, the automatic moving of notes onto the beat.

Quantizing intervalThe difference in voltage between quantizing levels.

Quantizing levelsThe number of possible values into which an analog signal may be divided or quantized.

RCA plugThe RCA company originally devised a plug for connecting phonographs (gramophone turntables) to amplifiers. These plugs became known as phonograph plugs, abbreviated to phono plugs.

ReverbContraction of 'reverberation’.

ReverberationThe sound made by reflections from a room, or an electrical simulation of this. It differs from echo in that there are so many reflections that individual reflections are not discernible. Reverberation time is measured as the time taken for the reflection level to decrease by 60 dB (RT60).

RIAA (Radio Industries Association of America)A trade association that also sets standards. Most often met is the RIAA standard for equalization of long playing gramophone records. When the disc is cut the high frequencies are boosted and the bass frequencies cut. This is corrected by reversing this on playback.

Ribbon micA microphone using a corrugated aluminium ribbon as a diaphragm. This is placed within the field of a powerful magnet. Once the standard microphone used by the BBC and other broadcasters, it is capable of extremely good quality especially on strings. It is advisable to take off your wristwatch before handling one as the strong magnetic field may stop it.

S/PDIF (Sony/Philips Digital Interface)Standardized digital audio connection format using an unbalanced audio connection and phono plugs.

SATA drive (Serial Advanced Technology Attachment)Nominally called the IDE (Integrated Drive Electronics) bus; it's also known as the A7”A (Advanced Technology Attachment) specification (ATA Bus). The IDE bus is a Parallel bus. A new form is being introduced called Serial ATA (SATA), as a result the parallel form is now commonly called parallel ATA (PATA).

SCMS (Serial Copy Management System)A specification for copy protection flags contained within domestic digital audio connections. While the system allows for no copy inhibition or full copy protection, its default is usually to allow only one digital copy; a SCMS equipped digital recorder will copy a digital recording set to allow one copy but the copy it makes will be set to no copying allowed. In practice the system is merely an annoyance for serious recordists working with original material. It can easily be defeated by analog copying, copying via a computer, or via an interface box that allows the resetting of the SCMS flags.

Scrub editingA term now used to describe the traditional way of finding edits on reel to reel tape which involved 'scrubbing’ the tape back and forth. Many users familiar with tape editing like to have this facility on a digital editor, although this usually soon turns out to be a security blanket.

SCSI (Small Computer Systems Interface)Usually pronounced ‘Scuzzy’. A way of connecting personal computers. Originally used on Apple Macintosh computers, it is regarded as having many technical advantages over its rival, IDE, universally used by PCs. However, there is no reason why a PC cannot use SCSI (some PC mother boards have it built-in, others can have a SCSI card fitted). Many people regard the extra expense worth the extra reliability it gives to audio recording. Both systems can be used within the same machine. The SCSI interface is also used for other devices like scanners. Seven devices plus the controller can be accommodated by a simple SCSI system, with fifteen devices available on more sophisticated systems.

SECAM (System En Couleur Avec Memoire)French color television system. SECAM VHS tapes will play in monochrome on a PAL video cassette machine.

SerialA term used when data is sent down one wire, one bit at a time.

SMPTE (Society of Motion Picture and Television Engineers)In conversation, often referred to as ‘Simty’; this body sets standards.

SMPTE/EBUThe combined American and European time code standard.

Stereo, stereophonyLiterally ‘Solid Sound’ from the Greek. While there is argument over a precise definition it seems generally to mean using two channels to give a directional effect. Good stereo will do more than this, giving a sense of depth as well as direction.

Table of contentsCompact Disc and Minidisc use a table of contents to tell them where each track and index begins and ends. If this is lost then the whole disc becomes unplayable.

TAO (Track At Once)Where a CD is burned one track at a time with one wave file per track. The laser is turned off between tracks.

Time codeA code contained within a recording that identifies each part of the tape uniquely in terms of time.

TinnitusA distressing condition caused by hearing damage where noises are generated within the ear, often perceived by the victim to be at a very loud level.

TOSLINK (TOShiba LINK)Optical connector used by many domestic digital audio devices.

TransientA short-lived sound, typically the leading and trailing edges of a note.

USB (Universal Serial Bus)A standard way of connecting apparatus to a computer that is supported by both PCs and Apple Mac computers. The devices are 'daisy-chained’ together and can be connected or disconnected without having to reboot the computer. The presently less common Firewire system is operationally similar but faster.

Variable pattern micThis contains two mic capsules that can be combined in different ways to give a range of directivities (see Page 191).

VarispeedA control for varying the speed of an analog recorder, usually on playback. This not only changes the rate but also the pitch. Digital editors usually have software that will allow change to rate or pitch independently of each other. Small changes of less than 10 per cent are usually very successful. Larger changes can suffer from glitches and artefacts. As a result you are often offered a choice of software methods (algorithms) which have different strengths and weaknesses.

VHS (Victor Home System)Presently the most popular home video tape format. In its NTSC version this has long play and extended play modes in addition to standard play. PAL systems only have a long play mode. The audio is recorded in two forms. There is a low quality recording on a linear track on the edge of the tape; this is usually mono but some machines provide stereo sometimes with Dolby noise reduction. Additionally many machines record in stereo using rotating heads within the video signal. The actual sound uses an FM carrier with a noise reduction using high-frequency pre-emphasis and 2 – 1 compression.

WAVThe .WAV format originated from Microsoft as a simple format for storing audio for games, etc. The format has been expanded for professional use adding text fields, etc. If an exported .WAV file begins with a click on another piece of software then it is possible that this software is not reading the file correctly. There is usually an option to export the files without the text information which can solve the problem. There is also an ADPCM version of this format giving 4 – 1 lossy compression. This is best regarded as an end-user format.

WMAWindows Media Audio. A Microsoft rival to MP3 files for streaming over the Internet.

WowSlow variation of pitch, traditionally caused by an off-centre gramophone record or a slipping capstan pulley on a tape machine. Digital audio systems are entirely free of this unless it is deliberately introduced as a special effect.

XLRConnector widely used in the professional audio field.

XY stereoIn the context of microphones this is sometimes used to indicate the use of a coincident pair of microphones as opposed to spaced (AB).

Zip driveProprietary form of removable hard disk cartridge.

Zip formatLossless data compression format much used to reduce the size of program and data files on disk and sent via modems. Unfortunately the assumptions that it makes do not apply to audio and files can end up larger after Zip compression than before.