Samsung HF4000 User Manual page 15

This function is available only on the Hands-Free profile. For more
information, see your phone's user manual.
Using options during a call
You can use the following functions during the call.
Adjusting the volume
Press the Volume up or down button to adjust the volume
You will hear a beep when the volume level of the hands-free car kit reaches
to the lowest or highest level
Muting the microphone
Press and hold the Volume up or down button to turn the microphone off so that
the person with whom you are speaking cannot hear you. When the microphone
is turned off, the hands-free car kit beeps at regular intervals and mic icon is
appeared. Press and hold the Volume up or down button again to turn the
microphone back on.
Transferring a call from the phone to the hands-free car kit
Press the Talk button to transfer a call from the phone to the hands-free car kit.
Placing a call on hold
Press and hold the Talk button to place the current call on hold.