Acronyms & Abbreviations Commonly Found in Music Discussions
The original idea for this appeared in a thread in July, 2006. Seemed like a good thing to expand and keep around in a sticky thread. Last update: January 23, 2012
For more info that you may not find here, check the
Audio Engineer's Online Dictionary which Frodo discovered for us!
For non-audio abbreviations and acronyms, especially internet slang, check
Wikipedia's List of Slang Phrases
For a fairly complete list of
audio data and file formats supported by OS X, be sure to check
this Apple Developer reference page.
AAC = Advanced Audio Coding: a standardized, lossy compression and encoding scheme for digital audio. AAC is considered the successor to the MP3 format by MP3’s creator, Fraunhofer IIS. AAC’s most famous usage is as the default audio format of Apple's iPhone, iPod, iTunes, and the format used for all iTunes Store audio (with extensions for proprietary Digital Rights Management (DRM) where used). --
Wikipedia.org
AAC = Advanced Audio Coding: Originally, the shortened name for the MPEG-2 Advanced Audio Coding specification, declared an international standard by MPEG in April 1997; however, now the term is used also to refer to MPEG-4 advanced audio coding.
A-B = Stereo Microphone Technique using two parallel omni mics placed 50 to 70 cm apart. Uses phase differences to create stereo image, thus not mono-compatible.
ADAT = Alesis Digital Audio Tape
ADC = Auto Delay Compensation (same as PDC)
ADR = Additional Dialogue Recording -- or-- Automatic Dialogue Replacement
ADSR = Attack/Decay/Sustain/Release - the envelope of linear dynamic flow in audio synthesis. Synthesizers use these four aspects as starting points for a note's envelope.
AES/EBU = Audio Engineering Society/European Broadcasting Union. Digital connection with connectors resembling those of XLR.
AIFC = Audio Interchange File Format: AIFC is AIFF with added provisions for compression encoding. AIFC files are almost universally readable by anything that can read AIFF, but
a new format introduced by Apple in OSX is currently output by Digital Performer in OS X 10.4. 9 and higher upon Bounce to Disk with AIFF selected, and the resulting AIFC file is of a type that may not be readable by older applications, thus the two are not necessarily interchangeable. Traditionally, AIFC is simply an AIFF file in which the compression chunk is set to a compression CODEC, rather than being left blank as in AIFF format.
AIFF-C/sowt Audio Interchange File Format - Compressed/sowt: A little-known audio file format introduced by Apple sometime in late 2006- early 2007 without documentation or announcement. While Apple's audio applications seemed unaffected (possibly because of insider information), others like Digital Performer were caught off-guard, and thus a bounce-to-disk with AIFF selected actually produces AIFF-C/sowt which shows up in the Finder as AIFC, but is not the same as the traditional AIFC format, which formerly was virtually interchangeable with AIFF.
See Wikipedia for Details.
AIFF = Audio Interchange File Format: developed by Apple for storing audio digitally in a lossless form on disk. Generally this means PCM format combined with "chunks" which are sections designated for name, author, instrument, annotation, MIDI Data, compression (in the case of AIFC) and other data.
AIFF on Wikipedia See also: PCM
ALAC = Apple Lossless (also known as Apple Lossless Encoder, ALE, or Apple Lossless Audio Codec) is an audio codec developed by Apple Inc. for lossless data compression of digital music. Apple Lossless data is stored within an MP4 container with the filename extension .m4a. While Apple Lossless has the same file extension as AAC, it is not a variant of AAC, but uses linear prediction similar to other lossless codecs such as FLAC and Shorten. iPods with a dock connector
(not the Shuffle) and recent firmware can play Apple Lossless-encoded files. It does not utilize any digital rights management (DRM) scheme, but by the nature of the container, it is thought that DRM can be applied to ALAC much the same way it can with other files in QuickTime containers.
APA = Waves' Audio Processing Accelerators (run Waves plugins via Ethernet)
APC = Automatic Pitch Correction
ATR = Audio Tape Recorder
ASCAP = American Society of Composers, Authors and Publishers
ASIO = Audio Streaming Input Output (audio driver developed by Steinberg)
au - the standard audio file format used by Sun, Unix and Java. The audio in au files can be PCM or compressed with the ulaw, alaw or G729 codecs.
AU = Audio Unit, Apple plug-in format
B = Bel. A relative measure of sound.
BDE = Beat Detection Engine
BE = Big Endian - In audio, a PCM format oriented toward "Mac" or Motorola processors. Little Endian and Big Endian have to do with byte order.
This reference page explains it all, plus gives practical advantages of the two formats
BMI = Broadcast Music Inc.
BNC = Bayonet Neill Concelman connector (named after the designer)
BTD = Bounce To Disk
BWAV = See BWF, Broadcast Wave Format.
BWF = Broadcast Wave Format. It is an extension of the popular Microsoft WAVE audio format and is the recording format of most file-based non-linear digital recorders used for motion picture and television production.
CAF = Core Audio Format. A Core Audio Format (CAF) file can contain audio data of any format. Any application that supports the CAF file format can write audio data to the file or extract the data it contains. However, the ability to encode or decode the audio data contained within it is dependent on the audio codecs available on the system.
CC = Control (or Controller) Channel
CC = MIDI Continuous Controller
CD = Compact Disk
CODEC = compressor/decompressor (or coder/decoder)
CPU = is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.
CRT = Cathode Ray Tube (computer monitor, television screen)
CW = Consolidated Window
CW = Continuous Wave
DA = short for digital-to-analog converter
DAE = Digidesign Audio Engine (or something like that), software audio engine used to drive digi hardware
DAW = Digital Audio Workstation
dB = Decibel. See "bel" above, just 1/10th
DC Notch = Digital Compensation adjustment plug to avoid DC offset (signal +/- zero amplitude)
DDP = Disc Description Protocol: a generic disc image file format commonly used for the transport of mastered audio CD data. Created by Doug Carson Associates (DCA), and also exists in an essentially identical format called CMF. It is the format preferred by replication facilities when submitting data for the replication of thousands or even millions of copies of CD's or DVD's. Standard Definition = DDP 2.0 or 2.1, while HD DVD = DDP 3.0.
DIGI = Digidesign (makers of Pro Tools)
DNU = do not use (use that as a label on files all the time!)
DP = Digital Performer
DSP = Digital Signal Processing
DVD = Digital Video Disc
EDL = "Edit Decision List"
See "OMF" below.
EQ = Equalizer or Equalization: balancing audio by frequency bands
FLAC = Free Lossless Audio Codec is a popular file format for audio data compression. Being a lossless compression format, FLAC does not remove information from the audio stream, as lossy compression formats such as MP3 and AAC do.
FPS = Frames Per Second
FSK = Frequency Key Shift: Audio time code consisting of a series of pulses which increment the counter of an FSK reading device.
FUD = Fear, Uncertainty and Doubt
FW = FireWire
GB = GigaByte: 1000 MegaBytes, or a billion bytes
GPO = Garritan Personal Orchestra (orchestral samples)
HD = Hard Drive
HD = high definition, among other things a newer ProTools format (as in: ProTools HD)
HDTV = High Definition Television
HUI = Human User Interface
Hz = Hertz. one cycle of a waveform.
IAMIDI = Interapplication MIDI
IDR = Increased Digital Resolution: Waves' noise-shaped dithering technology that works even with previously dithered data.
IEC = Electro-Technical Commission
ISO = International Standards Organization
ITB = In The Box: recording and mixing all take place inside the digital loop, involving a DAW, Digital Hardware, and plugins.
KB = KiloByte: 1000 bytes (or 1024, to be more precise)
kext = Kernel Extension
LAME = "
Lame
Ain't an
MP3
Encoder" And it's not. It's just a codec which acts as the number-crunching engine for MP3 encoder front-ends.
LCD = Liquid Crystal Display: the visual interface display of most calculators and other electronic (including musical) devices.
LDC = large diaphram condenser
LE = Little Endian - In audio, a PCM format oriented toward Intel processors. Little Endian and Big Endian have to do with byte order.
This reference page explains it all, plus gives practical advantages of the two formats
LFO = Low Frequency Oscillator
LTC = Longitudinal Time Code: SMPTE's time code format, expressed in audio form as an 80-bit binary audio signal, that describes the location of each frame on film, video, or audio tape in hrs., mins., sec., and frames. LTC is often referred to as SMPTE time code. Vertical (video) counterpart is VITC.
MAS = MOTU Audio System (or something like that), DP's own plug-in and software audio engine format
Mb = MegaBit.
MB = MegaByte: 1000,000 bytes
MBP = Mac Book Pro
ME = MIDI Editor
MIDI = Musical Instrument Digital Interface: information protocol developed in early 1980s by synth makers to network musical performance devices.
MMC = MIDI Machine Control
MOTU = Mark of the Unicorn
MP3 = MPEG-1 Layer-3 format: the most popular for downloading and storing music. By eliminating portions of the audio file that are essentially inaudible, mp3 files are compressed to roughly one-tenth the size of an equivalent PCM file while maintaining reasonably good audio quality. Higher quality encoders (see "LAME") yield higher quality audio. (not to be confused with MPEG-3, an abandoned HD video format)
MP4/m4a = (see MPEG-4) MPEG Layer-4 part 3, the portion of the MPEG-4 codec that includes the foundation for AAC encoding and DRM used in iTunes Music Store
MPEG-4 = MPEG Layer-4 : is a standard used primarily to compress audio and visual (AV) digital data. Introduced in late 1998, it is the designation for a group of audio and video coding standards and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG) under the formal standard ISO/IEC 14496. Portions of MPEG-4 are included under MPEG-1 & MPEG-2 codecs.
MPEG-4 -
part 3 (ISO/IEC 14496-3) Audio: A set of compression codecs for perceptual coding of audio signals, including some variations of Advanced Audio Coding (AAC) as well as other audio/speech coding tools. Apple's digital rights management (DRM) falls under the MPEG-4 standard.
MPEG-4 -
Quicktime Video H.264 = MPEG-4 Part 10 (ISO/IEC 14496-10): Advanced Video Coding (AVC): A codec for video signals which is technically identical to the ITU-T H.264 standard. In Quicktime, it is a fast, high-quality, highly compressed codec.
MPEG = Moving Pictures Experts Group; It is a group working under the directives of the ISO and the IEC to develop an evolving series of standards for compression of moving images. Members include companies such as Sony, Olympus, and others with audio and/or video compression interests. The standards produced by the group are notated with the MPEG acronym, which can be confusing. For example, MP3 refers to MPEG-1 layer 3, whereas MP4 generally is taken to be "slang" for MPEG-4 part 3 (AAC) or MPEG-4 part 10 (h.264), and MPEG-3 basically does not exist, representing a failed video codec.
M/S = Mid-side Technique: a stereo miccing technique that is mono-compatible, consisting of a bidirectional mic (figure 8 ) placed 90 degrees from source, with a forward facing cardioid in the same vertical space, and wired such that the cardioid feeds both channels equally, while the figure 8 mic cancels or reinforces off-axis source signals, subtracting or adding it to the cardioid's signal, creating a stereo image that can be varied by adjusting the relative volume of the mics.
MSI = MOTU Symphonic Instrument (orchestral samples)
MTC = MIDI Time Code: A form of time code, digitized within the MIDI format, expressing time in hours, minutes, seconds and frames, just like SMPTE (LTC and VITC)
MTP = MIDI Time Piece: MOTU's MIDI interface and MIDI Time Code syncronizer/generator
MTPAV or
MTP-AV = MIDI Time Piece AV (Audio Visual) MTP that syncs to ATRs, VTRs, Word Clocks, and other audio or visual equipment
MTU = Maximum Transmission Unit. Dictates the max size of ethernet packets.
MW = Master Works: DP's line of plugins, whose EQ--based on SSL or Neve type channel algorithms--is one of the best EQs available for DP.
NTSC = National Television System Committee: a color TV standard developed in the U.S. in 1953, using 30 fps for B&W and 29.97 fps for Color video signals. The United States, Canada, Japan, most of the Western Hemisphere and various Asian countries follow NTSC standards.
OGG = a free, open source container format supporting a variety of codecs, the most popular of which is the audio codec Vorbis. Vorbis offers better compression than MP3 but is less popular.
OMF =
Open Media Framework file format — also
OMFI -
Open Media Framework Interchange: Developed by Avid to assist in the exchange of sessions between different types of work-stations and the Pro Tools software platform. Includes "edit decision list," or
EDL which references the time stamps and in and out points of the audio files, like a map to reconstruct the session. OMF only supports audio data; MIDI and automation data are ignored. Effects plug-ins, EQs or other plugins are not included. Clips with pitch or time compression or expansion may disappear after OMF conversion if you forget to update the audio media and EDL reference.
OTB = Out of the box: when recording, either at an analog board, or the digital signal is converted to analog at some point during the mix.
PAL/SECAM = Phase Alternate Line is the TV standard introduced in the early 1960’s in Europe, utilizing 25 fps.
PCI = Peripheral Component Interconnect
PCM =
Pulse-code modulation: a digital representation of an analog signal where the magnitude of the signal is sampled regularly at uniform intervals, then quantized to a series of symbols in a digital (usually binary) code. PCM has been used in digital telephone systems and is also the standard form for digital audio in computers and the compact disc red book format. It is also standard in digital video, for example, using ITU-R BT.601. The audio data in a standard AIFF file are uncompressed big-endian pulse-code modulation (PCM).
PCMCIA = Personal Computer Memory Card International Association. This industry association was founded in 1989 to develop a standard for credit card sized removable personal computer adapters known as PC Cards.
PDC = Plugin Delay Compensation (see ADC)
PT = Pro Tools
QK = QuicKeys (macro automation program)
QS = QuickScribe
QT = Apple's Quicktime
Quan Jr. = Quantize Junior, (ie: dithering quantization)
RAM = Random Access Memory
RCA = Radio Corporation of America: also used to describe the plugs and jacks often seen on consumer audio equipment and VCRs. Usually color coded red, white, black, and yellow.
RCA = connector developed by RCA in the 40's to allow connection of phonographs to radios. Also called a phono plug.
REX = Recycle Export Format
RF64 = A BWF-compatible multichannel file format enabling file sizes to exceed 4 Gbyte. It has been specified by the European Broadcasting Union.
RTFM = Read the 'effin Manual.
S/PDIF = Sony/Philips Digital Interface: a standard audio transfer file format.
SBBOD = OSX specific, for "Spinning Beach Ball Of Death"
SDC = small diaphram condenser
SDII = Sound Designer II (two) - an audio file format used natively in Digital Performer and some other audio applications, though not nearly as widely used now (2006) as was true many years ago, when it used to be the default format for Pro Tools. It is basically an AIFF, with a little more info in the header.
SE = Sequence Editor
SECAM = Sequential Electronique Couleur avec Memoire: the broadcast television standard in France, Africa, the Middle East and most of Eastern Europe.
SMF = Standard MIDI File
SMPTE = Society of Motion picture and Television Engineers
SMPTE Time Code = SMPTE's protocol of binary impulses expressing location of each frame on film, video or audio tape in hours, minutes, seconds, and frames. It comes in two forms, an audio signal (see LTC) and a video signal (see VITC)
SNR = Signal to Noise ratio.
SPL = Sound Pressure Level. A measure of loudness.
SR = sample rate (i.e. 44.1 kHz)
SRC = sample rate converter/conversion, i.e. from 96kHz to 44.1kHz
SSL = Solid State Logic: British maker of high-quality mixing boards and audio equipment
SVCD = Super Video CD
SWR = Standing Wave Ratio
TDIF = Tascam Digital InterFace
TDM = Time Division Multiplexing (format by Digidesign for their higher-end hardware)
TO = Tracks Overview Window
TOSlink = ToshibaLink digital connector (optical)
TRS = Tip, Ring, Sleeve: audio jack/plug commonly known as quarter inch stereo plug, like that seen on headphones and patch cords
TT = Tiny Telephone: a type of patch-bay connector utilizing plugs that resemble slightly smaller TRS plugs.
UB = Universal Binary. Programs that contain both Power PC and Intel versions.
µ-law (pronouced "mu-law")= The µ-law algorithm: a companding algorithm, primarily used in the digital telecommunication systems of North America and Japan. As with other companding algorithms, its purpose is to reduce the dynamic range of an audio signal. In the analog domain, this can increase the signal-to-noise ratio (SNR) achieved during transmission, and in the digital domain, it can reduce the quantization error (hence increasing signal to quantization noise ratio).
USB = Universal Serial Bus
USB/MIDI = MIDI via the Universal Serial Bus. As more and more virtual instruments are replacing rack mounted units and keyboard-based MIDI instruments, the need for a MIDI interface diminishes. Many controllers are opting for direct USB connection like a mouse. While this allows for much finer control, most still use MIDI as the data format, simply because it is entrenched throughout the industry and can immediately interface with DAWs and VI's.
VCD = Video CD. A Video CD is a high-density optical storage medium. It can store data, typically up to 650 megabytes
VCO = Voltage Controlled Oscillator
VITC = Vertical Interval Time Code: SMPTE's time code format, expressed in video form as binary video signals recorded in the vertical blanking segment between frames, describing frame's location in hours, minutes, seconds, and frames. Audio counterpart is LTC.
VSO = Vienna Symphonic Orchestra (orchestral samples)
VCR = Video Cassette Recorder
VST = Virtual Studio Technology: Steinberg's universal plug-in format
VTR = Video Tape Recorder
WAV = WAVeform Audio Format. A Microsoft and IBM audio file format standard for storing audio on PCs. It is a variant of the RIFF bitstream format method for storing data in "chunks", and thus also close to the IFF and the AIFF format used on Amiga and Macintosh computers, respectively. It is the main format used on Windows systems for raw audio.
WUP = Waves Upgrade Plan
XLR = Ground/Left/Right
WUP = Waves Upgrade Plan
XLR = audio I/O plug, male and female, in which there are three pins: Ground/Left/Right.
X-Y = Stereo miccing technique using two directional mics placed at 90° or more to each other, with capsules in the same vertical space, one atop the other. Keeps phase differences to a minimum for mono compatibility. When both mics are
bidirectional and 90 degrees from each other, 45 degrees from source, they are called a Blumlein Pair.
Last major update January 23, 2012