A modem is disclosed. An embodiment thereof includes: a first interface arranged to connect to a network, a second interface arranged to connect to a host processor on the terminal, an audio interface arranged to connect to an audio processing means and a processing unit arranged to receive a plurality of parameters from the terminal via the second interface. The plurality of parameters are associated with a call established by the host processor to at least one further terminal connected to the network; wherein the processing unit is further arranged to receive input voice data from the audio processing means, process the input voice data in dependence on at least one of said parameters; and transmit the processed input voice data via the first interface to the at least one further terminal over said network during the call in dependence on a further at least one of said parameters.