The read-only audioLevel property of the RTCRtpContributingSource interface indicates the audio level contained in the last RTP packet played from the described source. audioLevel will be the level value defined in [RFC6465] if the RFC 6465 header extension is present, and otherwise null.


var audioLevel = RTCRtpContributingSource.audioLevel


A double-precision floating-point number which indicates the volume level of the audio in the most recently received RTP packet from the source described by the RTCRtpContributingSource.

This value, which is in the range 0.0 to 1.0, is on a linear scale and its value is defined in dBov, or decibels (overload). This is the amplitude relative to the point at which clipping of the audio begins to occur. A value of 1.0 represents 0 dBov (maximum volume), a value of 0.0 represents silence, and a value of 0.5 represents approximately 6 dB SPL (decibels of sound pressure level) change in the sound pressure level from 0 dBov.

For both RTCRtpContributingSource and RTCRtpSynchronizationSource, the audio level is converted to this form from the values defined in the specifications corresponding to each type of source.

audioLevel may be absent from RTCRtpContributingSource objects, which indicates that no volume level was provided by the source; however, it is required and always available on all RTCRtpSynchronizationSource objects.


Specification Status Comment
WebRTC 1.0: Real-time Communication Between Browsers
The definition of 'audioLevel' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support No ?591 No No ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support No No ?591 No ? ?

1. From version 59: this feature is behind the media.peerconnection.rtpsourcesapi.enable preference (needs to be set to true). To change preferences in Firefox, visit about:config.

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 Contributors to this page: fscholz, Sheppy, jpmedley
 Last updated by: fscholz,