Activating via the receiver during a call:

Press the speaker key and put down the receiver .

The key is lit up while the function is activated.

In speaker mode, you hear the caller via the speaker.

Deactivating speaker mode during a call:

Lift the receiver and continue the call via the receiver.

Listen mode:

During the call, press the speaker key. You will hear the caller via the speaker and the receiver, but only the microphone of the receiver will be active.