At a client, when first time data received from a server prior to continuous transmission of audio data of the server is set at a second timer, the second timer initiates time-counting from the set first time data. Accordingly, during the subsequent continuous transfer period of audio data, the timers of the server and client are adjusted to output the same time data in synchronization with each other. During the continuous transfer period, the client stores in a memory audio data that has been continuously transmitted according to the sequence to be output via a speaker from the server. The audio data is stored in the received sequence. Unit of audio data whose assigned first time data matches the second time data output from the second timer is searched for among the audio data in the memory to be output via the speaker.