During a conference call, participants who are not speaking should be as quiet as possible to minimize background noise on the call. The best method of keeping the call noise-free is for all participants to mute their land lines while they are not speaking. There are a few ways to do so.
Tap the "Mute" button on your land line phone after you dial in to the call. Tap the "Mute" button again to unmute when you want to speak.
Dial "_6" (Star 6) to mute your land line on many conference call services, if your phone does not have a "Mute" button. Dial "_6" again to unmute.
Ask the host of the call to inform you of the buttons to press to mute your phone on the call, if "*6" does not work.
Mute all phones, as the call host, by dialing the code for muting all callers except for the host phone. This is ideal when you want complete silence when you offer opening remarks. On some conference call services, muting all lines except for that of the host is done by dialing "*4" (Star 4).
Check the guidelines for your specific conference call for the exact code to press to mute all phones on your service.