A processing unit performs a method including controlling a reading-out of data from a first storage medium at a predetermined read-out data rate to produce inputted data, and controlling a compression of the inputted data to produce first compressed data of a first compressed format. The method includes controlling a storage of the first compressed data in a second storage medium at a faster writing data rate than the predetermined read-out data rate, controlling a reading-out of second compressed data of a second compressed format from the second storage medium, and controlling a decompression of the second compressed data to produce decompressed data. The method also includes controlling simultaneously the storage of the first compressed data in the second storage medium, the reading-out of the second compressed data from the second storage medium, and audibly reproducing the decompressed data. The first compressed format is different from the second compressed format.