Echo in the app occurs if the person you are talking to is not using headphones (i.e. they are playing sound out loud on speakers). When two people without headphones are within 20 meters of each other, this echo will form an infinite feedback loop, resulting in a terrible screeching noise. Generally, this disruption is filtered out by our Echo Cancelation software. However, in cases where it isn't, this echo/feedback can be prevented in the following ways:
1) Advise the user emitting echo/feedback to use headphones
2) Walk away from the user emitting the echo / feedback
3) Mute the user emitting echo / feedback (left click on their avatar and click “Mute” on the far left of their profile) or follow the steps in How do I mute other participants?).