| 摘要 |
PROBLEM TO BE SOLVED: To improve processing efficiency of speech processing based upon characteristics of human's auditory sense. SOLUTION: A speech encoding device 100 is equipped with a frequency conversion section 1 which frequency-converts an inputted speech signal, a band division section 2 which divides the frequency band of a frequency conversion coefficient obtained through the frequency conversion more narrowly for a lower band and more widely for a higher band based upon characteristics of human's auditory sense, a maximum value retrieval section 3 which retrieves a maximum value of the absolute value of the frequency conversion coefficient for each of the bands obtained by the band division section 2, a shift number calculation section 4 which calculates the number of shift bits so that the maximum value obtained by the maximum value retrieval section 3 for each of the bands is less than the number of quantized bits previously set for each of the bands, a shift processing section 5 which shifts the frequency conversion coefficient in each of the bands by the number of shift bits calculated by the shift number calculation section 4, and an encoding section 6 which encodes the signal subjected to the shift processing by a designated encoding system. COPYRIGHT: (C)2006,JPO&NCIPI
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