In a user terminal, a reproducing unit reads out from a music file memory unit a music file selected and input by a user and reproduces the music file. In a normal reproduction, an output unit outputs the reproduced sound as an audio. When a notification information reception unit receives information that needs to be noticed such as an e-mail or a phone call, a notification information analysis unit analyzes the setting of the information or notification sound and determines the degree of importance. A frequency band allocation unit selects from allocation patterns of frequency bands stored in an allocation information memory unit a pattern for the music and for the notification sound according to the degree of importance and the frequency band of the notification sound. An audio processing unit extracts and synthesizes the components of the frequency bands allocated to music and the notification sound, and the output unit outputs accordingly.