Your phones are configured to adjust the volume of both the ring as well as spoken word when on a call. Follow the steps below to adjust these two types of volume control.
To adjust ringer volume:
Press the left or right arrows when the handset is idle
Press the save soft key to accept the change or the back soft key to cancel
To adjust the call volume:
While on a call, press the left or right arrows to adjust the volume of the currently engaged audio devices (handset, earpiece, headset, or loud speaker)