How do I adjust the headset volume on the CT11/CT12?
To Adjust the Headset Volume:
The remote headset volume settings (Volume Low, Volume Medium, Volume High, and Volume Maximum) can only be adjusted during a call. Use the arrow keys to select the volume setting. When you hang up, the phone keeps the last volume setting selected.
Tip: When you press the arrow up key to the maximum volume level or the arrow down key to the lowest volume level, an error tone sounds.
To Setup the Ringer Volume:
Tip: If you select "Ringer Off", (Ringer Off) appears on the display when you make or receive calls, or when charging the remote.