See also:

Call volume
Adjusting the incoming or outgoing call volume may improve clarity if reception between callers is unclear. - Incoming calladjusting this setting allows you to hear a difference in volume. - ...

How to use brightness control and display ON/OFF button
To change the display brightness, push the button. Pushing the button again will change the display to the day or the night display. If no operation is performed within 5 seconds, the display ...

Speaker Adaptation (SA) mode
Speaker Adaptation allows up to two out-of dialect users to train the system to improve recognition accuracy. By repeating a number of commands, the users can create a voice model of their own ...