How to adjust the handset listen volume?

Method 1: Pickup your handset, and then press the volume adjust button.

Method 2: Preset the handset listen volume:

1. Press [Options]
2. Press [Up] / [Down] to locate "Volume adjustment..."
3. Press [Select]
4. Press [Up] / [Down] to locate "Handset listen"
5. Press [Select]
6. Press [Lower] / [Higher]
7. Press [Done]