Difference between revisions of "Digital audio" - New World Encyclopedia

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[[Image:Digital.signal.svg|thumb|right|A sound wave, in gray, represented digitally, in red (after a [[zero-order hold]] but before [[audio filter|filtering]])]]
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{{Images OK}}{{Approved}}{{copyedited}}
 
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[[Image:Pcm.svg|250px|thumb|right|Sampling and [[4-bit]] quantization of an analog signal (red) using [[Pulse-code modulation|Pulse Code Modulation.]]]]
'''Digital audio''' uses [[digital signal]]s for [[sound reproduction]]. This includes [[Analog-to-digital converter|analog-to-digital conversion]], [[Digital-to-analog converter|digital-to-analog conversion]], storage, and transmission.
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'''Digital audio''' is a [[technology]] that uses [[digital signal]]s for [[sound reproduction]]. It includes [[Analog-to-digital converter|analog-to-digital conversion]], [[Digital-to-analog converter|digital-to-analog conversion]], storage, and transmission.
 
 
Digital audio has emerged because of its usefulness in the recording, manipulation, mass-production, and distribution of sound. Modern distribution of music across the internet through on-line stores depends on digital recording and digital [[audio data compression|compression]] [[algorithm]]s. Distribution of audio as data files rather than as physical objects has significantly reduced costs of distribution.
 
 
 
From the [[wax cylinder]] to the [[compact cassette]], analogue audio music storage and reproduction have been based on the same principles upon which human hearing are based. In an analogue audio system, sounds begin as physical waveforms in the air, are transformed into an electrical representation of the waveform, via  a transducer (for example, a microphone), and are stored or transmitted.  To be re-created into sound, the process is reversed, through amplification and then conversion back into physical waveforms via a loudspeaker.  Although its nature may change, its fundamental wave-like characteristics remain unchanged during its storage, transformation, duplication, and amplification. All analogue audio signals are susceptible to noise and distortion, due to the inherent noise present in electronic circuits.
 
 
 
The digital audio chain begins when an analogue audio signal is converted into electrical signals — ‘on/off’ pulses — rather than electro-mechanical signals.  This signal is then further encoded to combat any errors that might occur in the storage or transmission of the signal.  This "channel coding" is essential to the ability of the digital system to recreate the analogue signal upon replay.  An example of a channel code is [[Eight-to-Fourteen Modulation|Eight to Fourteen Bit Modulation]] as used in the audio [[Compact Disc]].
 
  
 +
Digital audio has emerged because of its usefulness in the recording, manipulation, mass-production, and distribution of sound. Modern distribution of music across the Internet through on-line stores depends on digital recording and digital [[audio data compression|compression]] [[algorithm]]s. Distribution of audio as data files rather than as physical objects has significantly reduced costs of distribution.
 +
{{toc}}
 
==Overview of digital audio==
 
==Overview of digital audio==
 +
=== Going from analog to digital ===
 +
From the [[wax cylinder]] to the [[compact cassette]], analog audio music storage and reproduction have been based on the same principles upon which human hearing are based. In an analog audio system, sounds begin as physical waveforms in the air, are transformed into an electrical representation of the waveform, via  a transducer (for example, a microphone), and are stored or transmitted. To be recreated into sound, the process is reversed, through amplification and then conversion back into physical waveforms via a loudspeaker. Although its nature may change, its fundamental, wave-like characteristics remain unaltered during its storage, transformation, duplication, and amplification. All analog audio signals are susceptible to noise and distortion, due to the inherent noise present in electronic circuits.
  
[[Image:Pcm.svg|250px|thumb|right|Sampling and [[4-bit]] quantization of an analogue signal (red) using [[Pulse-code modulation|Pulse Code Modulation.]]]]
+
Digital audio is the technology of representing [[Sound recording and reproduction|audio]] in [[digital]] form. The digital audio chain begins when an analog audio signal is converted into electrical signals—"on/off" pulses—rather than electromechanical signals. This signal is then further encoded to combat any errors that might occur in the storage or transmission of the signal. This "channel coding" is essential to the ability of the digital system to recreate the analog signal upon replay. An example of a channel code is [[Eight-to-Fourteen Modulation|Eight to Fourteen Bit Modulation]] as used in the audio [[Compact Disc]].
  
Digital audio is the method of representing [[Sound recording and reproduction|audio]] in [[digital]] form.
+
An [[analog signal]] is converted to a [[digital signal]] at a given [[sampling rate]] and [[Audio bit depth|bit resolution]]; it may contain multiple channels (2 channels for [[Stereophonic sound|stereo]] or more for [[surround sound]]). Generally speaking, the higher the sampling rate and bit resolution, the greater the [[fidelity]], as well as higher the amount of digital data.
 
 
An [[analog signal]] is converted to a [[digital signal]] at a given [[sampling rate]] and [[Audio bit depth|bit resolution]]; it may contain multiple channels (2 channels for [[Stereophonic sound|stereo]] or more for [[surround sound]]).
 
Generally speaking: the higher the sampling rate and bit resolution the more [[fidelity]], as well as increase the amount of digital data.
 
  
 
===Sound quality===
 
===Sound quality===
While the goal of both analogue and digital systems is to reproduce audio perfectly, there are several obstacles to achieving this, including:
+
Although the goal of both analog and digital systems is to reproduce audio perfectly, there are several obstacles to achieving this goal. They include:
* '''Analogue''' [[noise floor]] in the capturing circuitry and have inherent [[capacitance]] and [[inductance]] that limit the [[Bandwidth (signal processing)|bandwidth]] of the system, and [[Electrical resistance|resistance]] that limits the [[amplitude]].
+
* '''Analog''' [[noise floor]] in the capturing circuitry, and have inherent [[capacitance]] and [[inductance]] that limit the [[Bandwidth (signal processing)|bandwidth]] of the system, and [[Electrical resistance|resistance]] that limits the [[amplitude]].
 
* '''Digital''' [[quantization noise]] in the capturing circuitry, and sampling rate limits the bandwidth and its bit resolution limits the [[dynamic range]] (resolution of amplitude creation).
 
* '''Digital''' [[quantization noise]] in the capturing circuitry, and sampling rate limits the bandwidth and its bit resolution limits the [[dynamic range]] (resolution of amplitude creation).
In order to achieve better fidelity, higher quality components are required, which increase overall cost.
+
In order to achieve better fidelity, higher quality components are required, which increased overall cost.
{{listen|filename=Quantization_noise.ogg|title=Quantization Noise|description=An example of audio with progressively worsening quantization noise.|format=[[Ogg]]}}
 
  
 
===Conversion process===
 
===Conversion process===
A digital audio signal starts with an [[analog-to-digital converter]] (ADC) that converts an analog signal to a digital signal. The ADC runs at a sampling rate and converts at a known bit resolution. For example, [[CD audio]] has a [[sampling rate]] of 44.1 [[kHz]] (44,100 samples per second) and 16-bit resolution for each channel (stereo). If the analog signal is not already [[bandlimited]] then an [[anti-aliasing filter]] is necessary before conversion, to prevent [[aliasing]] in the digital signal. (Aliasing occurs when frequencies above the [[Nyquist frequency]] have not been band limited, and instead appear as audible artifacts in the lower frequencies).
+
A digital audio signal starts with an [[analog-to-digital converter]] (ADC) that converts an analog signal to a digital signal. The ADC runs at a sampling rate and converts at a known bit resolution. For example, [[CD audio]] has a [[sampling rate]] of 44.1 [[kHz]] (44,100 samples per second) and 16-bit resolution for each channel (stereo). If the analog signal is not already [[bandlimited]], then an [[anti-aliasing filter]] is necessary before conversion, to prevent [[aliasing]] in the digital signal. (Aliasing occurs when frequencies above the [[Nyquist frequency]] have not been band limited, and instead appear as audible artifacts in the lower frequencies).
[[Image:Analogue Digital Conversion.png|400px|thumb|left|An overview of the digital <-> analogue conversion process.]]
+
[[Image:Analogue Digital Conversion.png|400px|thumb|left|An overview of the digital <-> analog conversion process.]]
  
 
Some audio signals such as those created by [[Synthesisers#The_modern_digital_synthesizer|digital synthesis]] originate entirely in the digital domain, in which case analog to digital conversion does not take place.
 
Some audio signals such as those created by [[Synthesisers#The_modern_digital_synthesizer|digital synthesis]] originate entirely in the digital domain, in which case analog to digital conversion does not take place.
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The digital audio signal may then be stored or transmitted.
 
The digital audio signal may then be stored or transmitted.
 
Digital audio storage can be on a [[CD]], an MP3 player, a [[hard drive]], [[USB flash drive]], [[CompactFlash]], or ''any'' other digital [[data storage device]].
 
Digital audio storage can be on a [[CD]], an MP3 player, a [[hard drive]], [[USB flash drive]], [[CompactFlash]], or ''any'' other digital [[data storage device]].
[[Audio data compression]] techniques — such as [[MP3]], [[Advanced Audio Coding]], [[Ogg Vorbis]], or [[Flac]] — are commonly employed to reduce the file size.
+
[[Audio data compression]] techniques—such as [[MP3]], [[Advanced Audio Coding]], [[Ogg Vorbis]], or [[Flac]]—are commonly employed to reduce the file size.
 
Digital audio can be [[Streaming media|streamed]] to other devices.
 
Digital audio can be [[Streaming media|streamed]] to other devices.
  
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Like ADCs, DACs run at a specific sampling rate and bit resolution but through the processes of [[oversampling]], [[upsampling]], and [[downsampling]], this sampling rate may not be the same as the initial sampling rate.
 
Like ADCs, DACs run at a specific sampling rate and bit resolution but through the processes of [[oversampling]], [[upsampling]], and [[downsampling]], this sampling rate may not be the same as the initial sampling rate.
  
==Subjective evaluation ==
+
==History of digital audio use in commercial recording==
{{Unreferencedsection|date=June 2008}}
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Commercial digital recording of classical and jazz music began in the early 1970s, pioneered by Japanese companies such as [[Denon]], the [[BBC]], and British record label [[Decca Records|Decca]] (which in the mid-70s developed digital audio recorders of their own design for mastering their albums), although experimental recordings existed from the 1960s.
Fidelity evaluation is a long-standing issue with audio systems in general and introduction of lossy compression algorithms and [[psychoacoustic]] models has only increased debate.
 
  
Audio can be measured and analyzed to more exacting measures than can be done by ear, but what this technical measurement and analysis lacks is the ability to determine if it sounds "good" or "bad" to any given listener.{{Dubious|date=March 2008}}
+
The first 16-bit PCM recording in the [[United States]] was made by [[Thomas Stockham]] at the [[Santa Fe Opera]] in 1976, on a [[Soundstream]] recorder. In most cases, there was no mixing stage involved; a stereo digital recording was made and used unaltered as the master tape for subsequent commercial release. These unmixed digital recordings are still described as [[SPARS Code|DDD]] since the technology involved is purely digital. (Unmixed analog recordings are likewise usually described as ADD to denote a single generation of analog recording.)
Like any other human opinion, there are numerous parameters that widely vary between people that affect their subjective evaluation of what is good or bad.
 
Such things that pertain to audio include hearing capabilities, personal preferences, location with respect to the speakers, and the room's physical properties.
 
  
This is not to say that subjective evaluation is unique to digital audio; digital audio can add to the fervor of discussion because it does introduce more things (e.g., lossy compression, psychoacoustic models) that can be debated.
+
Although the first-ever digital recording of a non-classical music piece, [[Morrissey-Mullen]]'s cover of the [[Rose Royce]] hit "[[Love Don't Live Here Anymore]]" (released 1979 as a [[Gramophone_record#Vinyl_quality|vinyl]] [[Extended play|EP]]) was recorded in 1978 at [[EMI]]'s  [[Abbey Road Studios|Abbey Road]] recording studios, the first entirely digitally recorded (DDD) popular music album was [[Ry Cooder]]'s ''[[Bop Till You Drop]],'' recorded in late 1978. It was unmixed, being recorded straight to a two-track [[3M]] digital recorder in the studio. Many other top recording artists were early adherents of digital recording. Others, such as former [[Beatles]] producer [[George Martin]], felt that the multitrack digital recording technology of the early 1980s had not reached the sophistication of analog systems. Martin used digital mixing, however, to reduce the distortion and noise that an analog master tape would introduce (thus ADD). An early example of an analog recording that was digitally mixed is [[Fleetwood Mac]]'s 1979 release, ''[[Tusk (album)|Tusk]]''.
  
==History of digital audio use in commercial recording==
+
==Subjective evaluation ==
Commercial digital recording of classical and jazz music began in the early 1970s, pioneered by Japanese companies such as [[Denon]], the [[BBC]], and British record label [[Decca Records|Decca]] (who in the mid-70s developed digital audio recorders of their own design for mastering of their albums), although experimental recordings exist from the 1960s. The first 16-bit PCM recording in the [[United States]] was made by [[Thomas Stockham]] at the [[Santa Fe Opera]] in [[1976]] on a [[Soundstream]] recorder. In most cases there was no mixing stage involved; a stereo digital recording was made and used unaltered as the master tape for subsequent commercial release. These unmixed digital recordings are still described as [[SPARS Code|DDD]] since the technology involved is purely digital. (Unmixed analogue recordings are likewise usually described as [[SPARS Code|ADD]] to denote a single generation of analogue recording.)
+
Fidelity evaluation is a long-standing issue with audio systems in general. Although audio signals can be measured and analyzed by specialized instruments to more exacting standards than can be done by ear, such measurements do not always reveal whether certain sounds are evaluated as "good" or "bad" by any given listener. Parameters that pertain to audio quality include hearing capabilities, personal preferences, location with respect to the speakers, and the room's physical properties. Of course, subjective evaluation is not unique to digital audio. However, digital audio adds more items to the debate, such as lossy compression algorithms and [[psychoacoustic]] models.
 
 
Although the first-ever digital recording of a non-classical music piece, [[Morrissey-Mullen]]'s cover of the [[Rose Royce]] hit ''[[Love Don't Live Here Anymore]]'' (released 1979 as a [[Gramophone_record#Vinyl_quality|vinyl]] [[Extended play|EP]]) was recorded in [[1978 in music|1978]] at [[EMI]]'s  [[Abbey Road Studios|Abbey Road]] recording studios, the first entirely digitally recorded (DDD) popular music album was [[Ry Cooder]]'s ''[[Bop Till You Drop]]'', recorded in late [[1978]]. It was unmixed, being recorded straight to a two-track [[3M]] digital recorder in the studio. Many other top recording artists were early adherents of digital recording. Others, such as former [[Beatles]] producer [[George Martin]], felt that the multitrack digital recording technology of the early 1980s had not reached the sophistication of analogue systems. Martin used digital mixing,{{Fact|date=January 2008}} however, to reduce the distortion and noise that an analogue master tape would introduce (thus ADD). An early example of an analogue recording that was digitally mixed is [[Fleetwood Mac]]'s 1979 release ''[[Tusk (album)|Tusk]]''.
 
  
 
==Digital audio technologies ==
 
==Digital audio technologies ==
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*[[TDIF]], [[Tascam]] proprietary format with [[D-sub]] cable
 
*[[TDIF]], [[Tascam]] proprietary format with [[D-sub]] cable
 
*[[Bluetooth]] via [[A2DP]]
 
*[[Bluetooth]] via [[A2DP]]
Naturally, any digital bus (e.g., [[Universal Serial Bus|USB]], [[FireWire]], and [[Peripheral Component Interconnect|PCI]]) can carry digital audio.
+
Naturally, any digital bus (such as [[Universal Serial Bus|USB]], [[FireWire]], and [[Peripheral Component Interconnect|PCI]]) can carry digital audio.
 +
 
 +
== See also ==
 +
* [[Compact Disc]]
 +
* [[DVD]]
 +
* [[Music]]
 +
* [[Sound]]
  
 
==References==
 
==References==
*Borwick, John, ed., 1994: ''Sound Recording Practice'' (Oxford: Oxford University Press)
+
* Borwick, John. 1996. ''Sound Recording Practice,'' 4th edition. Oxford: Oxford University Press. ISBN 0198166087.
*Ifeachor, Emmanuel C., and Jervis, Barrie W., 2002: ''Digital Signal Processing: A Practical Approach'' (Harlow, England: Pearson Education Limited)
+
* Ifeachor, Emmanuel C., and Barrie W. Jervis. 2002. ''Digital Signal Processing: A Practical Approach,'' 2nd edition. Harlow, UK: Prentice Hall. ISBN 0201596199.
*Rabiner, Lawrence R., and Gold, Bernard, 1975: ''Theory and Application of Digital Signal Processing'' (Englewood Cliffs, New Jersey: Prentice-Hall, Inc.)
+
* Rabiner, Lawrence R., and Bernard Gold. 1975. ''Theory and Application of Digital Signal Processing.'' Englewood Cliffs, NJ: Prentice-Hall. ISBN 0139141014.
*Watkinson, John, 1994: ''The Art of Digital Audio'' (Oxford: Focal Press)
+
* Stanley, William D., Gary R. Dougherty, and Ray Dougherty. 1984. ''Digital Signal Processing.'' Reston, VA: Reston Pub. Co. ISBN 083591321X.
 +
* Watkinson, John. 2005. ''The Art of Digital Audio,'' 3rd edition. Oxford: Focal Press. ISBN 0240515870.
  
==See also==
 
*[[Analog sound vs. digital sound]]
 
*[[Audio compression (data)]]
 
*[[Audio signal processing]]
 
*[[Digital audio editor]]
 
*[[Digital audio workstation]] (DAW)
 
*[[Mind the gap]], an early application of digital audio
 
*[[Musical Instrument Digital Interface]] (MIDI)
 
*[[Music sequencer]]
 
*[[Nyquist-Shannon sampling theorem]]
 
*[[Software synthesizer]]
 
*[[SPARS Code]] (re: ''DDD'' and ''ADD'')
 
*[[Audio bit depth|Bit depth]]
 
*[[Pulse-code modulation|Pulse Code Modulation]]
 
*[[Continuously variable slope delta modulation|Continuously Variable Slope Delta modulation]]
 
*[[High-Definition Multimedia Interface]] (HDMI)
 
  
 +
----
 
{{Digital systems}}
 
{{Digital systems}}
  
[[Category:Sound technology]]
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[[Category:Physical sciences]]
 +
[[Category:Communications technology]]
 +
 
  
[[ca:Àudio digital]]
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{{credit|228340392}}
[[da:Digital lyd]]
 
[[de:Digitalaudio]]
 
[[es:Audio digital]]
 
[[ko:디지털 오디오]]
 
[[id:Audio digital]]
 
[[it:Audio digitale]]
 
[[he:הקלטה דיגיטלית]]
 
[[nl:Digitale audio]]
 
[[ja:デジタルオーディオ]]
 
[[nn:Digital audio]]
 
[[pt:Som digital]]
 
[[uk:Цифровий звук]]
 

Latest revision as of 03:54, 29 July 2022

Sampling and 4-bit quantization of an analog signal (red) using Pulse Code Modulation.

Digital audio is a technology that uses digital signals for sound reproduction. It includes analog-to-digital conversion, digital-to-analog conversion, storage, and transmission.

Digital audio has emerged because of its usefulness in the recording, manipulation, mass-production, and distribution of sound. Modern distribution of music across the Internet through on-line stores depends on digital recording and digital compression algorithms. Distribution of audio as data files rather than as physical objects has significantly reduced costs of distribution.

Overview of digital audio

Going from analog to digital

From the wax cylinder to the compact cassette, analog audio music storage and reproduction have been based on the same principles upon which human hearing are based. In an analog audio system, sounds begin as physical waveforms in the air, are transformed into an electrical representation of the waveform, via a transducer (for example, a microphone), and are stored or transmitted. To be recreated into sound, the process is reversed, through amplification and then conversion back into physical waveforms via a loudspeaker. Although its nature may change, its fundamental, wave-like characteristics remain unaltered during its storage, transformation, duplication, and amplification. All analog audio signals are susceptible to noise and distortion, due to the inherent noise present in electronic circuits.

Digital audio is the technology of representing audio in digital form. The digital audio chain begins when an analog audio signal is converted into electrical signals—"on/off" pulses—rather than electromechanical signals. This signal is then further encoded to combat any errors that might occur in the storage or transmission of the signal. This "channel coding" is essential to the ability of the digital system to recreate the analog signal upon replay. An example of a channel code is Eight to Fourteen Bit Modulation as used in the audio Compact Disc.

An analog signal is converted to a digital signal at a given sampling rate and bit resolution; it may contain multiple channels (2 channels for stereo or more for surround sound). Generally speaking, the higher the sampling rate and bit resolution, the greater the fidelity, as well as higher the amount of digital data.

Sound quality

Although the goal of both analog and digital systems is to reproduce audio perfectly, there are several obstacles to achieving this goal. They include:

  • Analog noise floor in the capturing circuitry, and have inherent capacitance and inductance that limit the bandwidth of the system, and resistance that limits the amplitude.
  • Digital quantization noise in the capturing circuitry, and sampling rate limits the bandwidth and its bit resolution limits the dynamic range (resolution of amplitude creation).

In order to achieve better fidelity, higher quality components are required, which increased overall cost.

Conversion process

A digital audio signal starts with an analog-to-digital converter (ADC) that converts an analog signal to a digital signal. The ADC runs at a sampling rate and converts at a known bit resolution. For example, CD audio has a sampling rate of 44.1 kHz (44,100 samples per second) and 16-bit resolution for each channel (stereo). If the analog signal is not already bandlimited, then an anti-aliasing filter is necessary before conversion, to prevent aliasing in the digital signal. (Aliasing occurs when frequencies above the Nyquist frequency have not been band limited, and instead appear as audible artifacts in the lower frequencies).

An overview of the digital <-> analog conversion process.

Some audio signals such as those created by digital synthesis originate entirely in the digital domain, in which case analog to digital conversion does not take place.

After being sampled with the ADC, the digital signal may then be altered in a process which is called digital signal processing where it may be filtered or have effects applied.

The digital audio signal may then be stored or transmitted. Digital audio storage can be on a CD, an MP3 player, a hard drive, USB flash drive, CompactFlash, or any other digital data storage device. Audio data compression techniques—such as MP3, Advanced Audio Coding, Ogg Vorbis, or Flac—are commonly employed to reduce the file size. Digital audio can be streamed to other devices.

The last step for digital audio is to be converted back to an analog signal with a digital-to-analog converter (DAC). Like ADCs, DACs run at a specific sampling rate and bit resolution but through the processes of oversampling, upsampling, and downsampling, this sampling rate may not be the same as the initial sampling rate.

History of digital audio use in commercial recording

Commercial digital recording of classical and jazz music began in the early 1970s, pioneered by Japanese companies such as Denon, the BBC, and British record label Decca (which in the mid-70s developed digital audio recorders of their own design for mastering their albums), although experimental recordings existed from the 1960s.

The first 16-bit PCM recording in the United States was made by Thomas Stockham at the Santa Fe Opera in 1976, on a Soundstream recorder. In most cases, there was no mixing stage involved; a stereo digital recording was made and used unaltered as the master tape for subsequent commercial release. These unmixed digital recordings are still described as DDD since the technology involved is purely digital. (Unmixed analog recordings are likewise usually described as ADD to denote a single generation of analog recording.)

Although the first-ever digital recording of a non-classical music piece, Morrissey-Mullen's cover of the Rose Royce hit "Love Don't Live Here Anymore" (released 1979 as a vinyl EP) was recorded in 1978 at EMI's Abbey Road recording studios, the first entirely digitally recorded (DDD) popular music album was Ry Cooder's Bop Till You Drop, recorded in late 1978. It was unmixed, being recorded straight to a two-track 3M digital recorder in the studio. Many other top recording artists were early adherents of digital recording. Others, such as former Beatles producer George Martin, felt that the multitrack digital recording technology of the early 1980s had not reached the sophistication of analog systems. Martin used digital mixing, however, to reduce the distortion and noise that an analog master tape would introduce (thus ADD). An early example of an analog recording that was digitally mixed is Fleetwood Mac's 1979 release, Tusk.

Subjective evaluation

Fidelity evaluation is a long-standing issue with audio systems in general. Although audio signals can be measured and analyzed by specialized instruments to more exacting standards than can be done by ear, such measurements do not always reveal whether certain sounds are evaluated as "good" or "bad" by any given listener. Parameters that pertain to audio quality include hearing capabilities, personal preferences, location with respect to the speakers, and the room's physical properties. Of course, subjective evaluation is not unique to digital audio. However, digital audio adds more items to the debate, such as lossy compression algorithms and psychoacoustic models.

Digital audio technologies

  • Digital Audio Broadcasting (DAB)
  • Digital audio workstation
  • Digital audio player

Storage technologies:

Digital audio interfaces

Audio-specific interfaces include:

  • AC97 (Audio Codec 1997) interface between Integrated circuits on PC motherboards
  • Intel High Definition Audio A modern replacement for AC97
  • ADAT interface
  • AES/EBU interface with XLR connectors
  • AES47, Professional AES3 digital audio over Asynchronous Transfer Mode networks
  • I²S (Inter-IC sound) interface between Integrated circuits in consumer electronics
  • MADI Multichannel Audio Digital Interface
  • MIDI low-bandwidth interconnect for carrying instrument data; cannot carry sound
  • S/PDIF, either over coaxial cable or TOSLINK
  • TDIF, Tascam proprietary format with D-sub cable
  • Bluetooth via A2DP

Naturally, any digital bus (such as USB, FireWire, and PCI) can carry digital audio.

See also

References
ISBN links support NWE through referral fees

  • Borwick, John. 1996. Sound Recording Practice, 4th edition. Oxford: Oxford University Press. ISBN 0198166087.
  • Ifeachor, Emmanuel C., and Barrie W. Jervis. 2002. Digital Signal Processing: A Practical Approach, 2nd edition. Harlow, UK: Prentice Hall. ISBN 0201596199.
  • Rabiner, Lawrence R., and Bernard Gold. 1975. Theory and Application of Digital Signal Processing. Englewood Cliffs, NJ: Prentice-Hall. ISBN 0139141014.
  • Stanley, William D., Gary R. Dougherty, and Ray Dougherty. 1984. Digital Signal Processing. Reston, VA: Reston Pub. Co. ISBN 083591321X.
  • Watkinson, John. 2005. The Art of Digital Audio, 3rd edition. Oxford: Focal Press. ISBN 0240515870.




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