Samsung SCH-1530 - Manual (Page 40)

Calling Options
32
Mute Microphone
You can mute the microphone during conversation by selecting
the Mute option from the In Use Menu. When Mute is active,
“MUTE” displays, instead of the call timer. The phone resets
this condition to the default “unmute” setting at call end.
To mute the microphone:
1. During conversation, press to display the In Use
Menu.
2. Press to mute the microphone. You will hear the
other party’s conversation, but they will not hear your
conversation.
3. To “unmute” the microphone during the same
conversation, repeat Steps 1-2. Selecting the (Un)mute
option toggles Mute on and off.