When you hear echos, there's a good chance that a co-host is using the build-in speaker instead of headphones.
Under such circumstances, the sounds of the live stream will go off through the speaker and then it is picked up by the build -in microphone, which cause listeners hear an echo.
To resolve such an issue, co-hosts can mute their mics when not speaking so that the rest of listeners can only hear the speaker.
In case the echo issue still persists after doing that, please send us an email and describe the problem by going to the "Account" tab - "Settings" - "Contact us" - "Report a tech issue".