The close() method of the AudioContext Interface closes the audio context, releasing any system audio resources that it uses.
Compression lowers the volume of the loudest parts of the signal and raises the volume of the softest parts. Overall, a louder, richer, and fuller sound can be achieved. It is especially important in games and musical applications where large numbers of individual sounds are played simultaneously, where you want to control the overall signal level and help avoid clipping (distorting) of the audio output.
For more details about media element audio source nodes, check out the MediaElementAudioSourceNode reference page.
The MediaStream is created when the node is created and is accessible via the MediaStreamAudioDestinationNode's stream attribute. This stream can be used in a similar way as a MediaStream obtained via navigator.getUserMedia — it can, for example, be sent to a remote peer using the RTCPeerConnection addStream() method.
For more details about media stream audio source nodes, check out the MediaStreamAudioSourceNode reference page.
The panner node is spatialized in relation to the AudioContext's AudioListener (defined by the AudioContext.listener attribute), which represents the position and orientation of the person listening to the audio.
This is the preferred method of creating an audio source for Web Audio API from an audio track.