ATRAC-3-Plus

The speech compression technology which SONY developed. Those which improve"ATRAC3 " of the same company. It is adopted for network walkman and the like of the same company.Ifthe sound quality like CD it is assumedthat it becomes furthermore 1 of the half 20 parts of ATRAC3.

With ATRAC3plus, the aural signal is divided into the frequency zone16it is 4 times that ATRAC3withthe bandwidth division
filter. After that, fromthe time based data string it converts to the frequency based data string with Modified, DCT (deformation dispersion cosine conversion) it compresses encodes. Rise of further conversion efficiency is assured this time,by designating conversion section as length of former 2 times.