When using automatic gain control (AGC), the phone tries to maintain a constant audio level even if the incoming call changes between loud and quiet.

1.Press the key menu MENU button.
2.Use the up arrow up and down down arrow arrow keys to highlight Advanced Options. Press Select.
3.Use the up arrow up and down down arrow arrow keys to highlight Audio. Press Select.
Use the up arrow up and down down arrow arrow keys to switch between Handset, Headset, or Speaker settings for AGC.
To change the highlighted setting, press Change.
4.When completed, press Save.
5.Press Back / Exit to exit the menus.