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{{short description|Representation of sound, typically as an electrical voltage}}
An '''audio signal''' is a representation of [[sound]], typically as an electrical [[voltage]] for [[analog signal]]s and a binary number for [[digital signal]]s. Audio signals have frequencies in the [[audio frequency]] range of roughly 20 to 20,000 Hz (the [[Human hearing range|limits of human hearing]]). Audio signals may be [[Synthesizer|synthesized]] directly, or may originate at a [[transducer]] such as a [[microphone]], [[Pickup (music technology)|musical instrument pickup]], [[phonograph]] cartridge, or [[tape head]]. [[Loudspeaker]]s or [[headphones]] convert an electrical audio signal into sound.
{{One source|date=August 2020}}

An '''audio signal''' is a representation of [[sound]], typically using either a changing level of electrical [[voltage]] for [[analog signal]]s, or a series of [[binary numbers]] for [[Digital signal (signal processing)|digital signal]]s. Audio signals have frequencies in the [[audio frequency]] range of roughly 20 to 20,000 Hz, which corresponds to the lower and upper [[Human hearing range|limits of human hearing]]. Audio signals may be [[Synthesizer|synthesized]] directly, or may originate at a [[transducer]] such as a [[microphone]], [[Pickup (music technology)|musical instrument pickup]], [[phonograph cartridge]], or [[tape head]]. [[Loudspeaker]]s or [[headphones]] convert an electrical audio signal back into sound.


[[Digital audio]] systems represent audio signals in a variety of digital formats.<ref>Hodgson, Jay (2010). ''Understanding Records'', p.1. {{ISBN|978-1-4411-5607-5}}.</ref>
[[Digital audio]] systems represent audio signals in a variety of digital formats.<ref>Hodgson, Jay (2010). ''Understanding Records'', p.1. {{ISBN|978-1-4411-5607-5}}.</ref>


An '''audio channel''' or '''audio track''' is an audio signal [[Channel (communications)|communications channel]] in a [[data storage device|storage device]] or [[mixing console]], used in operations such as [[multi-track recording]] and [[sound reinforcement]].
An '''audio channel''' or '''audio track''' is an audio signal [[communications channel]] in a [[data storage device|storage device]] or [[mixing console]]. It is used in operations such as [[multi-track recording]] and [[sound reinforcement]].


== Signal flow ==
== Signal flow ==
[[Audio signal flow|Signal flow]] is the path an audio signal will take from source to the speaker or recording device. Signal flow may be short and simple as in a [[home audio]] system or long and convoluted in a [[recording studio]] and larger sound reinforcement system as the signal may pass through many sections of a large [[Mixing console|console]], external [[audio equipment]], and even different rooms.
[[Signal flow]] is the path an audio signal will take from source to the speaker or recording device. Signal flow may be short and simple as in a [[home audio]] system or long and convoluted in a [[recording studio]] and larger sound reinforcement system as the signal may pass through many sections of a large mixing console, external [[audio equipment]], and even different rooms.


==Parameters==
==Parameters==
Audio signals may be characterized by parameters such as their [[Bandwidth (signal processing)|bandwidth]], [[nominal level]], [[Electric power|power]] level in [[decibel]]s (dB), and voltage level. The relation between power and voltage is determined by the [[Electrical impedance|impedance]] of the signal path, which may be [[Single-ended signalling|single-ended]] or [[Balanced line|balanced]].
Audio signals may be characterized by parameters such as their [[Bandwidth (signal processing)|bandwidth]], [[nominal level]], [[Electric power|power]] level in [[decibel]]s (dB), and voltage level. The relationship between power and voltage is determined by the [[Electrical impedance|impedance]] of the signal path. Signal paths may be [[Single-ended signalling|single-ended]] or [[Balanced audio|balanced]].


Audio signals have somewhat standardized levels depending on application. Outputs of professional [[Mixing console|mixing consoles]] are most commonly at [[line level]]. Consumer audio equipment will also output at a lower line level. Microphones generally output at an even lower level, commonly referred to a ''mic level''.<!--[[User:Kvng/RTH]]-->
Audio signals have somewhat standardized levels depending on the application. Outputs of professional mixing consoles are most commonly at [[line level]]. Consumer audio equipment will also output at a lower line level. Microphones generally output at an even lower level, known as ''mic level''.


== Digital equivalent ==
== Digital equivalent ==
As much of the older [[Analog signal|analog]] audio equipment has been [[Software emulator|emulated]] in [[Digital audio|digital]] form, usually through the development of [[audio plug-in]]s for [[digital audio workstation]] (DAW) software, the path of digital information through the DAW (i.e. from an audio track through a plug-in and out a hardware output) is also called an ''audio signal'' or ''signal flow''.{{cn|date=October 2017}}
The digital form of an audio signal is used in [[audio plug-in]]s and [[digital audio workstation]] (DAW) software. The digital information passing through the DAW (i.e. from an audio track through a plug-in and out a hardware output) is an audio signal.


A digital audio signal being sent through wire can use several formats including [[optical]] ([[ADAT]], [[TDIF]]), [[coaxial]] ([[S/PDIF]]), [[XLR connector|XLR]] ([[AES/EBU]]), and [[Audio over Ethernet|Ethernet]].
A digital audio signal can be sent over [[optical fiber]], [[coaxial]] and [[twisted pair]] cable. A [[line code]] and potentially a [[communication protocol]] are applied to render a digital signal for a transmission medium. Digital audio transports include [[ADAT]], [[TDIF]], [[TOSLINK]], [[S/PDIF]], [[AES3]], [[MADI]], [[audio over Ethernet]] and [[audio over IP]].


==See also==
==See also==
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*[[Analog recording]]
*[[Analog recording]]
*[[Audio editing software]]
*[[Audio editing software]]
*[[Audio Engineering Society]]
*[[Audio engineer]]
*[[Audio signal processing]]
*[[Audio signal processing]]
*[[Balanced audio]]
*[[Communications]]
*[[Digital recording]]
*[[Digital recording]]
*[[Equalization (audio)]]
*[[Equalization (audio)]]
*[[Octophonic sound]]
*[[Professional audio]]
*[[Professional audio]]
*[[Psychoacoustics]]
*[[Psychoacoustics]]
*[[Quadraphonic sound]]
*[[Sound editor (filmmaking)|Sound editing]]
*[[Sound engineer]]
*[[Sound intensity]]
*[[Sound intensity]]
*[[Sound recording and reproduction]]
*[[Sound recording and reproduction]]
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==External links==
==External links==
*{{Commonscat-inline|Audio signal}}
*{{Commons category-inline|Audio signal}}


[[Category:Musical terminology]]
[[Category:Musical terminology]]

Latest revision as of 15:37, 8 July 2024

An audio signal is a representation of sound, typically using either a changing level of electrical voltage for analog signals, or a series of binary numbers for digital signals. Audio signals have frequencies in the audio frequency range of roughly 20 to 20,000 Hz, which corresponds to the lower and upper limits of human hearing. Audio signals may be synthesized directly, or may originate at a transducer such as a microphone, musical instrument pickup, phonograph cartridge, or tape head. Loudspeakers or headphones convert an electrical audio signal back into sound.

Digital audio systems represent audio signals in a variety of digital formats.[1]

An audio channel or audio track is an audio signal communications channel in a storage device or mixing console. It is used in operations such as multi-track recording and sound reinforcement.

Signal flow

[edit]

Signal flow is the path an audio signal will take from source to the speaker or recording device. Signal flow may be short and simple as in a home audio system or long and convoluted in a recording studio and larger sound reinforcement system as the signal may pass through many sections of a large mixing console, external audio equipment, and even different rooms.

Parameters

[edit]

Audio signals may be characterized by parameters such as their bandwidth, nominal level, power level in decibels (dB), and voltage level. The relationship between power and voltage is determined by the impedance of the signal path. Signal paths may be single-ended or balanced.

Audio signals have somewhat standardized levels depending on the application. Outputs of professional mixing consoles are most commonly at line level. Consumer audio equipment will also output at a lower line level. Microphones generally output at an even lower level, known as mic level.

Digital equivalent

[edit]

The digital form of an audio signal is used in audio plug-ins and digital audio workstation (DAW) software. The digital information passing through the DAW (i.e. from an audio track through a plug-in and out a hardware output) is an audio signal.

A digital audio signal can be sent over optical fiber, coaxial and twisted pair cable. A line code and potentially a communication protocol are applied to render a digital signal for a transmission medium. Digital audio transports include ADAT, TDIF, TOSLINK, S/PDIF, AES3, MADI, audio over Ethernet and audio over IP.

See also

[edit]

References

[edit]
  1. ^ Hodgson, Jay (2010). Understanding Records, p.1. ISBN 978-1-4411-5607-5.
[edit]