Customer hears echo during calls.
In a voice call, echo occurs when you hear your own voice repeated. There are 2 ways echo can occur:
1. Electronically through poor cabling or latency. Review / replace cabling, or address latency issue.
2. Acoustic feedback through sound waves between speakers & microphones. Ask other party to lower the volume to reduce feedback.
Note: Hands free speakers & conference calls are especially sensitive to echo. Suggest muting when not talking.