Sometimes, echoes are caused by using speaker phones, polycom phones, headsets, cell phones, having international callers, or may just be a bad connection. Callers can use *6 to mute and un-mute their lines as needed. The conference host can mute all the participants (besides the presenter) using the customized dashboard and host controls to eliminate ambient/disruptive noises. For a quick resolution, press *0 for operator assistance.