Based on user identification data transmitted together with a compressed data from a portable reproducing apparatus, if an apparatus recognizes that a user who purchased and downloaded the compressed data is the same as a user who owns the apparatus, the audio apparatus stores and holds the compressed data after reproducing the signal from the compressed data by the decoder unit and the data processing unit. Alternatively, if it recognizes that the user who purchased and downloaded the compressed data is not the same as the user who owns the apparatus, it removes the compressed data after reproducing the signal from the compressed data by the decoder unit and the data processing unit.