| 摘要 |
PURPOSE: To improve tone quality on auditory sensation by coding an inputted sound signal after gain controlling at a frequency characteristic opposite to the frequency characteristic based on an auditory model. CONSTITUTION: A sound signal coding device 50 is provided with a pre-emphasis- filter 51 gain controlling the frequency characteristic of the inputted sound signal S50 so as to optimize it when weighting on the prestage of an encoder 52. Further, a sound signal decoding device 60 is provided with a de-emphasis- filter 62 correcting the frequency characteristic on the post-stage of a decoder 61. Then, the inputted sound signal is coded after it is gain-controlled at the frequency characteristic opposite to the frequency based on the auditory model. Thus, the number of bits allocated to a frequency band easy to be recognized on the auditory sensation are increased when the sound signal is coded, and the number of bits allocated to the frequency band hard to be recognized are reduced, and the tone quality is improved. |
