[. . . ] [. . . ] Many telephones incorporate a dedicated port for headset use, but where there isn't one and amplification is not required, the Plantronics Bi-Way switch provides the ideal solution. Please refer to your headset user guide for details of how to maximise the use of your headset. Plug your headset into the port showing a headset symbol on the rear of the Bi-Way switch. I cannot hear callers/callers cannot hear me To use the Bi-Way with your headset, make sure that the switch is set to headset mode Check that each cable is fitted correctly, and in the correct port Clear or replace the voice tube. [. . . ] [. . . ]