To provide a system which can easily change an operational sound of electronic equipment in a home by using a cellular phone unit while ensuring safety in data transmission.

A content-distribution system is provided with; a cellular phone unit provided with a memory part which stores content data acquired from a content-providing server via a network, a memory part which stores the number of effective days for using the content, the number of deletion day for deleting the content, and the number of times of allowed transmission, an infrared communication means, and a counting means which counts the number of times of transmitting content; and a sound-source reproduction device provided with an infrared communication means, which performs infrared communication with the cellular phone unit, and a reproduction means which reproduces a sound based on the content data. The number of deletion days is set longer than the number of the effective days. When it is after lapse of the number of effective days and before the number of deletion days, the cellular phone unit distinguishes the results of the counting made by the counting means. When there is no frequency of transmission, the cellular phone unit transmits the content data to the sound-source reproduction device.