The objective of the present invention is to enable a speaker to visually confirm whether or not his voice has reached a listener. In order to achieve this objective, in the present invention, the listener terminal generates a reception result for voice data, and the talker terminal displays the reception state based on this reception result.
It is a further objective of the present invention to enable conversational timing to be achieved easily. In order to achieve this objective, in the present invention, the talker terminal sends utterance data prior to sending voice data, this utterance data being shorter than the voice data. The listener terminal displays the talker terminal's utterance based on this utterance data.
Another objective of the present invention is to deliver voice data from the talker terminal to a particular listener terminal only, without having to form a private group. In order to achieve this objective, in the present invention, the server stores permission or denial for sending data from an optional terminal to another optional terminal, and distributes the voice data based on this storage.