Patent ID: 6975732

Claim:
A compact audio signal reproducing apparatus comprising a memory unit for storing digitized and high-efficiency compression encoded audio data; a decoder for reading out data stored in said memory unit and decoding the read-out data by performing an inversion of the compression encoding; a digital/analog converter for converting output signals from said decoder into analog signals; a headphone unit for said analog signals from said digital analog converter and converting said analog signals from said digital/analog converter into acoustic signals; and a housing for containing said memory unit, said decoder, and said digital/analog converter, said housing being compact, wherein said audio data is compression encoded by sub-band dividing audio data by dividing said audio data into a plurality of frequency bands, and quantizing a frequency component transformed from audio data for each of said plurality of frequency bands according to a masking spectrum associated with said frequency component for each of said plurality of frequency bands and a minimum audible curve based on the human auditory sense.