# Plugin Demo: Web Audio Processing

Want to learn more about the EchoTest plugin? Check the Documentation.

### Demo details

This is a variant of the Echo Test demo meant to showcase how you can use the Web Audio API to manipulate the audio from the microphone, before sending it to Janus, using some dynamic controls to tweak the output. The remote audio, echoed back by Janus, is also processed via Web Audio and rendered visually.

Notice that this is just a basic example, and is not meant as a comprehensive tutorial on how to use Web Audio, but only as a simple indication of how they can indeed be used with Janus WebRTC streams.

Also notice that this demo does not negotiates video for the sake of simplicity, in order to only focus on audio controls and visualization.

Press the `Start` button above to launch the demo.

Local Stream (compressor)
Threshold
Knee
Ratio
Attack
Release
Remote Stream (visualizer)