Aastra 6771/6773/6775 (OpenPhone 71/73/75) System Phones19It is also possible to enable a second person to listen in on a call over a connectedheadset while you are telephoning over the handset. To enable, press the headset keyduring the call. Listening-in over the headset is now activated, the LED on the headsetkey flashes.Enquiry KeyR To initiate and end an enquiry call. After you have ended an enquiry call, switchback to the call being held with this key.Plus/Minus Key= This key offers various functions which depend on the device status:• It adjusts the volume during open-listening/hands-free mode.• It adjusts the volume when making a call via the handset.• It adjusts the volume of the headphones of a headset (the volume of the micro-phone can be adjusted over the Phone settings MenuCard, see page 114).• It adjusts the volume of the ringer tone during a call.• It sets the contrast of the display when the telephone is in the idle state.• It switches features on/off quickly.• It changes the volume of the ringer tone and the melody in the Phone settingsMenuCard.• It moves the cursor when entering call numbers or text.Tip: If you have already used the plus/minus key to open a menu toset the display contrast or the volume, your current setting willautomatically be applied after three seconds, without your usingthe OK key O to confirm.ESC Keye (Escape key) navigates the menu.• Short key press: Exits an open input window without changing its contents and/orreturns you to the menu branches.• Long key press: Exits the menu.
