36 Customizing radio settingsYou may be able to use a function key to change the volumeof your keypress tones in the following ways:■ Press the assigned function key to change the volume ofyour radio’s keypress tones between high and low.■ Press the assigned function key to turn keypress toneseither on or off.Changing to quiet operationWhen quiet operation is on, keypress tones and confirmationtones are turned off. Incoming call tones, signalling tones andwarning tones all remain audible.To turn quiet operation on or off:■ Press the assigned function key.Changing to silent operationWhen silent operation is on, all the radio’s audible tones areturned off, and only channel traffic can be heard.To turn silent operation on or off:■ Press the assigned function key.Changing backlighting settingsWhenever a key is pressed or a call is received, the keypad anddisplay light up automatically. Backlighting only remains onfor a few seconds, unless there is further radio activity.You may be able to use a function key to change the way yourbacklighting operates in the following ways:■ Press the assigned function key to turn backlighting on.Backlighting remains on for a few seconds, and thenturns off.■ Press the assigned function key to turn backlighting on.Backlighting then remains on until there is a furtherkey press■ Short press the assigned function key to turn backlightingon momentarily. Long press the assigned function key toturn backlighting on. Backlighting then remains on untilthere is a further long key press.