When echoing or feedback occurs in the audio during a Zoom meeting, it could be the result of one of the following causes:
- A participant has both the computer and telephone audio active
- Participants using computer or telephones speakers that are too close to each other
- Multiple computers with active audio in the same conference room
A quick way to resolve the issue is to mute all participants, which will give you time to investigate and resolve the cause.
Further help regarding these issues is available on the Zoom support page, Audio Echo in a Meeting.