The read-only audioLevel property of the RTCRtpContributingSource dictionary contains 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.

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.