Patent ID: 7580893
Filing Date: 2009-08-25
Classification: G10L

Abstract:
1. An acoustic signal apparatus including an encoder and a decoder each having a processor and a memory with the apparatus being configured to perform an acoustic signal coding and decoding method adapted to encode and decode a time domain signal, the method comprising the steps of: dividing the time domain signal into a plurality of frequency bands by a subband filter in the encoder; detecting an amplitude of the time domain signal in each of the plurality of frequency bands in units of sub-block length resulted from division of a block length in which the time domain signal is to be coded by an amplitude analyzer in the encoder; controlling the amplitude of the time domain signal based on amplitude controlling information of at least one selected frequency band of the frequency bands detected during the amplitude detecting step by a normalization unit in the encoder; transforming to a frequency component the time domain signal for which the amplitude was processed during the amplitude controlling step; encoding the transformed time domain signal, the amplitude controlling information and an encoding key information into a code row by a encryption unit in the encoder; sending the code row to the decoder by the encoder; determining whether a time parameter exceeds predetermined period information by the decoder; decoding the code row based on the time parameter determining step by the decoder; comparing a supplied key information to the encoded key information by a key information checking unit in the decoder; determining whether the supplied key information is equal to the encoded key information by a key information checking unit in the decoder; and based on the supplied key determining step generating an acoustic signal with the incorrect amplitude by the amplitude processor.