Glossary: D

D major is a major scale based on D, consisting of the pitches D, E, F♯, G, A, B, and C♯. Its key signature has two sharps. Its relative…

D minor is a minor scale based on D, consisting of the pitches D, E, F, G, A, B♭, and C. Its key signature has one flat. Its relative…

D-flat major is a major scale based on D♭, consisting of the pitches D♭, E♭, F, G♭, A♭, B♭ and C. Its key signature has five flats.

D-flat minor is a musical key based on D♭, consisting of the pitches D♭, E♭, F♭, G♭, A♭, B, and C♭. Because its key signature has eight…

D-sharp minor is a minor scale based on D♯, consisting of the pitches D♯, E♯, F♯, G♯, A♯, B, and C♯. Its key signature has six sharps.

D A D G A D, or Celtic tuning, is an alternative guitar tuning most associated with Celtic music, though it has also found use in rock…

In the recording industry, a dakou (Chinese: 打口) was a type of cut-out used in China to gain access to mostly rock music recordings that…

The Dallas Rangemaster Treble Booster was an effects unit made for guitarists in the 1960s. Its function was two-fold: to increase the…

In an audio power amplifier, the damping factor is defined as the ratio of the rated impedance of the loudspeaker (usually assumed to be 8…

"Dancing in the Street" is a song written by Marvin Gaye, William Stevenson, and Ivy Jo Hunter for Martha and the Vandellas in 1964, whose…

The Danelectro Amp-In-Case, properly known as a semi-hollow body due to its Masonite top and back, with pine outer structure. "All-in-one"…

The Danelectro Commando is a combo guitar amplifier manufactured by Danelectro from 1954 to 1960. There is some evidence that it may be…

"Dark Was the Night, Cold Was the Ground" is a gospel blues song written and performed by American musician Blind Willie Johnson and…

The Dassault Mirage III is a family of single/dual-seat, single-engine, fighter aircraft developed and manufactured by French aircraft…

In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than…

DataPlay is an optical disc system developed by DataPlay Inc. and released to the consumer market in 2002. Using tiny (32mm-diameter)…

The Dattorro industry scheme is a digital system used to implement a wide range of delay-based audio effects for digital signals. It was…

David Tranter is an Indigenous Australian sound recordist and filmmaker. He is known for his collaborations with Warwick Thornton, in…

The dawn chorus is the outbreak of birdsong at the start of a new day.

The "Day of Infamy" speech, sometimes referred to as the Infamy speech, was a speech delivered by Franklin D. Roosevelt, the 32nd…

Day of Silence is an annual day of action organized by GLSEN (Gay, Lesbian & Straight Education Network) to spread awareness about the…

The day-night average sound level (Ldn or DNL) is the average noise level over a 24-hour period. The noise level measurements between the…

The day–evening–night noise level or Lden is a 2002 European standard to express noise level over an entire day. It imposes a penalty on…

dB drag racing is a competition rewarding the person who can produce the loudest sound inside a vehicle. The "dB" means decibels of sound…

dBFS or dB FS (decibels relative to full scale) is a unit of measurement for amplitude levels in digital systems, such as pulse-code…

dbx is a family of noise-reduction systems developed by the company of the same name. The most common implementations are dbx Type I and…

DC-International is an analog audio cassette format developed by Grundig and marketed in 1965. DC is the abbreviation of "Double…

De-essing (also desibilizing) is any technique intended to reduce or eliminate the excessive prominence of sibilant consonants, such as…

The Deacy Amp is an electric guitar amplifier created in 1972 by Queen's bassist John Deacon, who is an electronics engineer by training.

Some strains of animals, such as white cats, have a tendency to congenital deafness. Some known chemicals and elements can also affect…

Deaf culture encompasses the social beliefs, behaviors, arts, traditions, history, values, and institutions of communities that are shaped…

Deaf hearing refers to a condition in which deaf individuals are able to react to an auditory stimulus, without actually being able to…

Deaf mental health care is the providing of counseling, therapy, and other psychiatric services to people who are deaf and hard of hearing…

Deaf peddlers are people who sell to the wider public manual alphabet cards, keychains, nail clippers, pencils and pens, national flags…

Deaf philosophy is an emerging sub-field of philosophy covering bioethics, metaphysics, epistemology, while also including elements of…

Deaf and hard of hearing individuals with additional disabilities are referred to as "Deaf Plus" or "Deaf+". Deaf children with one or…

The Deaf rights movement encompasses a series of social movements within the disability rights and cultural diversity movements that…

Deaf theology is a modern theological perspective that frames theological issues through a Deaf lens. The scope of Deaf theology is mostly…

Deaf-mute is a term which was used historically to identify a person who was either deaf and used sign language or both deaf and could not…

Deafness has varying definitions in cultural and medical contexts. In medical contexts, the meaning of deafness is hearing loss that…

The Windward Islands are a group of islands in the Caribbean Sea that include Dominica, Martinique, Barbados, Saint Lucia, Saint Vincent…

Deafness-vitiligo-achalasia syndrome is an extremely rare genetic disorder characterized by congenital hearing loss, vitiligo, low height…

Deafnet (or DEAFNET) was created as a demonstration project in 1978 by SRI International (previously known as Stanford Research Institute)…

#DeafTalent is a hashtag used to highlight through social media the capabilities of the deaf and hard of hearing community. Prior to the…

"Dear Mama" is a song by American rapper 2Pac from his third studio album, Me Against the World (1995). It was released on February 9…

A death rattle is noisy breathing that often occurs in someone near death. Accumulation of fluids such as saliva and bronchial secretions…

The Decca Tree is a spaced microphone array most commonly used for orchestral recording. It was originally developed as a type of stereo…

The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a…

The decibel watt (dBW or dBW) is a unit for the measurement of the strength of a signal expressed in decibels relative to one watt.

Deeper Smart Sonar is a wireless, castable echo-sounder compatible with iOS and Android smartphones and tablets. Wi-Fi connection enabled…

A deer horn, or deer whistle, is a whistle mounted on automobiles intended to help prevent collisions with deer. Air moving through the…

Deiters' cells, also known as outer phalangeal cells or cells of Deiters (English: ), are a cell type found within the inner ear. They…

Delayed auditory feedback (DAF), also called delayed sidetone, is a type of altered auditory feedback that consists of extending the time…

Delivered Audio Quality, abbreviated as DAQ, is a measure of audio quality over a transmission medium. This metric is often used to…

A demo (shortened from "demonstration") is a song or group of songs typically recorded for limited circulation or for reference use…

Denon DL103 is an MC (moving coil) phono cartridge made by DENON company.

Dereverberation is the process by which the effects of reverberation are removed from sound, after such reverberant sound has been picked…

DeSanctis–Cacchione syndrome is a genetic disorder characterized by the skin and eye symptoms of xeroderma pigmentosum (XP) occurring in…

Despacio, usually styled as DESPACIO, is a live musical performance and the name of the custom-built sound system on which it is played.

Deterministic Networking (DetNet) is an effort by the IETF DetNet Working Group to study implementation of deterministic data paths for…

Deutsch's scale illusion is an auditory illusion in which two series of unconnected notes appear to combine into a single recognisable…

A DI unit (direct input or direct inject) is an electronic device typically used in recording studios and in sound reinforcement systems…

Diabetes and deafness (DAD) or maternally inherited diabetes and deafness (MIDD) or mitochondrial diabetes is a subtype of diabetes which…

Identification of a hearing loss is usually conducted by a general practitioner medical doctor, otolaryngologist, certified and licensed…

Dialogic listening is an alternative to active listening which was developed by John Stewart and Milt Thomas. The word ‘dialogue’…

The diamond buffer or diamond follower is a four-transistor, two-stage, push-pull, translinear emitter follower, or less commonly source…

In acoustics, a diaphragm is a transducer used for the conversion between mechanical vibrations and sounds. It is commonly constructed of…

Diatonic and chromatic are terms in music theory that are used to characterize scales. The terms are also applied to musical instruments…

The diatonic, Guidonian, or major hexachord (6-32) is a hexachord consisting of six consecutive pitches from the diatonic scale that are…

Dichotic listening is a psychological test commonly used to investigate selective attention and the lateralization of brain function…

In Audiology, dichotic pitch (or the dichotic pitch phenomenon) is a pitch heard due to binaural processing, when the brain combines two…

The Dictabelt, in early years and much less commonly also called a Memobelt, is an analog audio recording medium commercially introduced…

Dictaphone was an American company founded by Alexander Graham Bell that produced dictation machines. It is now a division of Nuance…

A dictation machine is a sound recording device most commonly used to record speech for playback or to be typed into print. It includes…

Diffuse field acoustic testing is the testing of the mechanical resistance of a spacecraft to the acoustic pressures during launch.

Diffusion, in architectural acoustics, is the spreading of sound energy evenly in a given environment. A perfectly diffusive sound space…

Digital Audio Broadcasting (DAB) is a digital radio standard for broadcasting digital audio radio services in many countries around the…

The Digital Audio Stationary Head or DASH standard is a reel-to-reel, digital audio tape format introduced by Sony in early 1982 for…

Digital Audio Tape (DAT or R-DAT) is a discontinued digital recording and playback medium developed by Sony and introduced in 1987.

In signal processing, a digital biquad filter is a second order recursive linear filter, containing two poles and two zeros, which…

Digital audio cassette formats introduced to the professional audio and consumer markets:

Digital Compact Cassette (DCC) is a discontinued magnetic tape sound recording format introduced by Philips and Matsushita Electric in…

A digital delay line (or simply delay line, also called delay filter) is a discrete element in a digital filter that allows a signal to be…

Digital eXtreme Definition (DXD) is a digital audio format that originally was developed by Philips and Merging Technologies for editing…

The Digital Performance Right in Sound Recordings Act of 1995 (DPRA) is a United States Copyright law that grants owners of a copyright in…

In digital recording, an audio or video signal is converted into a stream of discrete numbers representing the changes over time in air…

Digital room correction (or DRC) is a process in the field of acoustics where digital filters designed to ameliorate unfavorable effects…

The Digital Sound System 80, short DSS80, was a three-piece PC audio system co-developed by Microsoft and Philips. It debuted at the 1998…

Digital speakers or digital sound reconstruction (DSR) systems are a form of loudspeaker technology. Not to be confused with modern…

Digital waveguide synthesis is the synthesis of audio using a digital waveguide. Digital waveguides are efficient computational models…

The DigiTech JamMan is a discontinued looper pedal formerly manufactured by DigiTech. It is unrelated to the earlier Lexicon JamMan unit…

The DigiTech Whammy is a pitch shifter pedal manufactured by DigiTech. It raises or lowers the pitch of an audio signal by up to two…

Diminished tuning is a system of choosing the reeds for a diatonic wind instrument (such as a harmonica or accordion) in which the blow…

In Western music and music theory, diminution (from Medieval Latin diminutio, alteration of Latin deminutio, decrease) has four distinct…

DingDong is a line of smart speakers created by Chinese company Ling Long (a partnership between JD.com and iFlytek). The metal A1 was…

The Diogenes Club is a fictional gentlemen's club created by Sir Arthur Conan Doyle and featured in several Sherlock Holmes stories, such…

Diplacusis, also known as diplacusis binauralis, binauralis disharmonica or interaural pitch difference (IPD), is a hearing disorder…

A direct acoustic cochlear implant (DACI) is an acoustic implant which converts sound in mechanical vibrations that stimulate directly the…

Direct metal mastering (DMM) is an analog audio disc mastering technique jointly developed by two German companies, Telefunken-Decca…

Direct Stream Digital (DSD) is a trademark used by Sony and Philips for their system for digitally encoding audio signals for the Super…

Direct-field acoustic testing, (DFAT), is a technique used for acoustic testing of aerospace structures by subjecting them to sound waves…

A directional siren is a siren with a bandwidth broader than 500 Hz-1.8 kHz that enables listeners to more quickly locate the source of…

Directional sound refers to the notion of using various devices to create fields of sound which spread less than most (small) traditional…

Directive 2011/77/EU on the term of protection of copyright and certain related rights amended Directive 2006/116/EC and extended the…

In electromagnetics, directivity is a parameter of an antenna or optical system which measures the degree to which the radiation emitted…

A disc jockey, more commonly abbreviated as DJ, is a person who plays recorded music for an audience. Types of DJs include radio DJs (who…

A discomix, or simply a disco, is an extended reggae 12-inch single that typically features the vocal track followed by a dub version or a…

In information theory and signal processing, the Discrete Universal Denoiser (DUDE) is a denoising scheme for recovering sequences over a…

In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and…

Distortion and overdrive are forms of audio signal processing used to alter the sound of amplified electric musical instruments, usually…

Distortion synthesis is a group of sound synthesis techniques which modify existing sounds to produce more complex sounds (or timbres)…

Distributed Mode Loudspeaker (DML) is a flat-panel loudspeaker technology, developed by NXT, in which sound is produced by inducing…

Dither or dithering is an intentionally applied form of noise used to randomize quantization error, preventing large-scale patterns such…

In music, a ditone (Latin: ditonus, from Ancient Greek: δίτονος, "of two tones") is the interval of a major third. The size of a ditone…

A ditonic scale is a musical scale or mode with two notes per octave. This is in contrast to a heptatonic (seven-note) scale such as the…

DIY Audio, do it yourself audio. Rather than buying a piece of possibly expensive audio equipment, such as a high-end audio amplifier or…

A DJ mixer is a type of audio mixing console used by disc jockeys (DJs) to control and manipulate multiple audio signals. Some DJs use the…

DMG Clearances, Inc is a company based in Hockessin, Delaware, USA, which handles music clearances and licensing for the entertainment…

Dolby Atmos is a surround sound and spatial sound technology developed by Dolby Laboratories. It expands on existing surround sound…

Dolby Cinema is a type of premium large format movie theater designed by Dolby Laboratories that combines Dolby proprietary technologies…

Dolby Digital, originally synonymous with Dolby AC-3 (see below), is the name for a family of audio compression technologies developed by…

Dolby Headphone is a technology developed by Lake Technology (Australia), that later sold marketing rights to Dolby Laboratories…

A Dolby noise-reduction system (Dolby NR) is one of a series of noise reduction systems developed by Dolby Laboratories for use in analog…

Dolby Pro Logic is a surround sound processing technology developed by Dolby Laboratories, designed to decode soundtracks encoded with…

Dolby Stereo is a sound format made by Dolby Laboratories. It is a unified brand for two completely different basic systems: the Dolby SVA…

Dolby Surround 7.1 (sometimes called Dolby 7.1 surround sound) is a surround sound system by Dolby Laboratories which delivers theatrical…

Dolby TrueHD is a lossless, multi-channel audio codec developed by Dolby Laboratories for home video, used principally in Blu-ray Disc and…

Dolby Vision is a set of technologies developed by Dolby Laboratories and Christie Digital Systems for high-dynamic-range (HDR) video. It…

In music, the dominant is the fifth scale degree of the diatonic scale. It is called the dominant because it is second in importance to…

"Don't Stop Believin'" is a song by American rock band Journey. It was released in October 1981 as the second single from the group's…

"Don't Worry, Be Happy" is a 1988 song by Bobby McFerrin, released as the lead single from his album Simple Pleasures (1988). It was the…

The Doppler effect (also Doppler shift) is the change in the frequency or, equivalently, the period of a wave in relation to an observer…

The dorsal cochlear nucleus (DCN, also known as the "tuberculum acusticum") is a cortex-like structure on the dorso-lateral surface of the…

A double album (or double record) is an audio album that spans two units of the primary medium in which it is sold, typically either…

Double MS recording is an audio recording technique used to record surround sounds using three microphones. The mid mic usually a cardioid…

Double tracking or doubling is an audio recording technique in which a performer sings or plays along with their own prerecorded…

The double-density compact disc (DDCD) is an optical disc technology developed by Sony and Philips using the same 780 nm laser wavelength…

"Down by the Riverside" (also known as "Ain't Gonna Study War No More" and "Gonna lay down my burden") is an African-American spiritual.

Downstep is a phenomenon in tone languages in which if two syllables have the same tone (for example, both with a high tone or both with a…

A dramatic soprano is a type of operatic soprano with a powerful, rich, emotive voice that can sing over, or cut through, a full orchestra.

Drifting Intervals is an ambient music technique developed by Czech musician and sound artist Vojtech Vesely, known by his stage name De…

Drop C tuning is an alternative guitar tuning where at least one string has been lowered to a C, but most commonly refers to CGCFAD, which…

Drop D tuning is an alternative form of guitar tuning in which the lowest (sixth) string is tuned down from the usual E of standard tuning…

A dropped ceiling is a secondary ceiling, hung below the main (structural) ceiling. It may also be referred to as a drop ceiling, T-bar…

Drum replacement is the practice, in modern music production, of an engineer or producer recording a live drummer and replacing (or adding…

DTS (an initialism of its original name, Digital Theater Systems) is an American company that makes multichannel audio technologies for…

DTS-HD Master Audio (DTS-HD MA; known as DTS++ before 2004) is a multi-channel, lossless audio codec developed by DTS as an extension of…

The DualDisc is a double-sided optical disc developed by a group of record companies including MJJ Productions Inc., EMI Music, Universal…

A dubplate is an acetate disc usually of 10 inches diameter, traditionally used by studios to test recordings prior to mastering for the…

In audio engineering, ducking is an audio effect commonly used in radio and pop music, especially dance music. In ducking, the level of…

The acoustic pressure in a cylindrical duct can be expressed as the superposition of duct modes:

The Overdrive Special is a guitar amplifier made by Dumble Amplifiers. Founder Howard Alexander Dumble first began producing what would…

The Dunlop Cry Baby is a wah-wah pedal, manufactured by Dunlop Manufacturing, Inc. The name Cry Baby was from the original pedal from…

Duplex perception refers to the linguistic phenomenon whereby "part of the acoustic signal is used for both a speech and a nonspeech…

The dust cap (also known as dust dome, or dome) is a gently curved dome mounted either in concave or convex orientation over the central…

"Dust My Broom" is a blues song originally recorded as "I Believe I'll Dust My Broom" by American blues artist Robert Johnson in 1936. It…

DVD (Digital Video Disc or Digital Versatile Disc) is a digital optical disc data storage format. It was invented and developed in 1995…

DVD-Audio (commonly abbreviated as DVD-A) is a digital format for delivering high-fidelity audio content on a DVD. DVD-Audio uses most of…

DVD-RAM (DVD Random Access Memory) is a DVD-based disc specification presented in 1996 by the DVD Forum, which specifies rewritable…

DVD-Video is a consumer video format used to store digital video on DVDs. DVD-Video was the dominant consumer home video format in most of…

The DVDplus is a dual-sided disc similar to the DualDisc. It is an optical disc storage technology that combines the technology of DVD and…

In music, a dyad (less commonly, diad) is a set of two notes or pitches. The notes of a dyad can be played simultaneously or in…

Dynagroove is a recording process introduced in 1963 by RCA Victor that, for the first time, used analog computers to modify the audio…

In diagnostic ultrasound, dynamic aperture is the ability to adjust the number of active receive elements as a function of depth to…

Dynamic binaural recording is a type of binaural recording where the sound source appears to change position with the change in position…

The Dynamic Noise Limiter, or DNL for short, is a noise reduction system introduced by Philips in the late 1960s to improve the quality of…

Dynamic range (abbreviated DR, DNR, or DYR) is the ratio between the largest and smallest measurable values of a specific quantity. It is…

Dynamic range compression (DRC) or simply compression, is an audio signal processing operation that reduces the volume of loud sounds or…

Dynamic tonality is a paradigm for tuning and timbre which generalizes the special relationship between just intonation and the harmonic…

Dynamical energy analysis (DEA) is a method for numerically modelling structure borne sound and vibration in complex structures.

Dynaquad, or DY, was a matrix decoder 4-channel quadraphonic sound system developed by Dynaco in 1969.