 | This articlerelies largely or entirely on asingle source. Relevant discussion may be found on thetalk page. Please helpimprove this article byintroducing citations to additional sources. Find sources: "Audio signal" – news ·newspapers ·books ·scholar ·JSTOR(August 2020) |
Anaudio signal is a representation ofsound, typically using either a changing level of electricalvoltage foranalog signals or a series ofbinary numbers fordigital signals. Audio signals have frequencies in theaudio frequency range of roughly 20 to 20,000 Hz, which corresponds to the lower and upperlimits of human hearing. Audio signals may besynthesized directly, or may originate at atransducer such as amicrophone,musical instrument pickup,phonograph cartridge, ortape head.Loudspeakers orheadphones convert an electrical audio signal back into sound.
Digital audio systems represent audio signals in a variety of digital formats.[1]
Anaudio channel oraudio track is an audio signalcommunications channel in astorage device ormixing console. It is used in operations such asmulti-track recording andsound reinforcement.
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 ahome audio system, or long and convoluted in arecording studio and larger sound reinforcement system, as the signal may pass through many sections of a large mixing console, externalaudio equipment, and even different rooms.
Audio signals may be characterized by parameters such as theirbandwidth,nominal level,power level indecibels (dB), and voltage level. The relationship between power and voltage is determined by theimpedance of the signal path. Signal paths may besingle-ended orbalanced.
Audio signals have somewhat standardized levels depending on the application. Outputs of professional mixing consoles are most commonly atline level. Consumer audio equipment will also output at a lower line level. Microphones generally output at an even lower level, known asmic level.
The digital form of an audio signal is used inaudio plug-ins anddigital 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 overoptical fiber,coaxial andtwisted pair cable. Aline code and potentially acommunication protocol are applied to render a digital signal for a transmission medium. Digital audio transports includeADAT,TDIF,TOSLINK,S/PDIF,AES3,MADI,audio over Ethernet andaudio over IP.
Media related toAudio signal at Wikimedia Commons