To enable various notification sounds suiting users' tastes to be fetched in a host unit without replacing a device or the like.

A LAN connection terminal and a PHS card connection terminal are provided to the host unit 2 of an interphone device to connect the interphone device to an internet N1, and a dedicated server 7 where notification sound data are stored is arranged on the internet N1. In the interphone device, a sound data selection/acquisition button for selecting and acquiring notification sound data from the dedicated server 7, a sound data memory input/output function, and a sound data reproduction function are provided to the host unit 2, so that the notification sound data can be downloaded from the dedicated server 7 to the host unit 2. A personal computer 37 where notification sound data are stored is connected to the LAN connection terminal through the intermediary of a router 6, whereby the notification sound data stored in the personal computer 37 can be downloaded directly to the host unit 2.