If you hear audio echo or audio feedback during your meeting, there are three possible causes:
The source of echo can also be from speakers (such as TV or soundbar) that are too loud, failed echo cancellation (device or performance issue), or a bad microphone. Generally, if you are hearing echo, it means that there is a device that is channeling your audio back.
To isolate the attendee:
This article covers:
If you join from a computer and call in from the telephone, ensure that you follow the steps below:
If another participant is too close to you and both of you have speakers on, leave audio conference on one of the computers or hang up the the telephone connections.
If you are in a conference room with multiple devices, disconnect computer audio from the other devices. For more information about disconnecting computer audio from computers, see Joining a meeting or webinar by phone.
Note: Muting is not enough as you mute the mic, but the speaker is still on.
To disconnect computer audio from the mobile (Android and iOS) devices: