Aastra 53I IP PHONE - RELEASE 2.1 User Manual page 90

IP Phone UI
Press the button at any time to mute handset, headset, or handsfree.
The speaker light will flash slowly and you can hear the caller, but they cannot hear
you. To switch mute on or off, press .
Note: If you place a muted call on hold, the phone automatically takes the call
off mute when you reconnect to the call.
82 Model 53i IP Phone User Guide