| 摘要 |
PURPOSE:To obtain a reproduced sound with high sound quality. CONSTITUTION:The device is provided with coding sections 1, 2, 3, 4, 5 and decoding sections 7, 8, 9. A block length decision section 1 of a coding section applies time division to an input signal into a block length in response to a change degree. A frequency band division section 2 divides each block signal into plural frequency bands. A bit distribute section 3 obtains a masking threshold level versus noise ratio of each frequency band based on the power of each frequency band while reflected on an auditory psychological characteristic and decides a quantization bit number to be distributed to each frequency band based on the quantity of the masking threshold level versus noise ratio. A quantization section 4 quantizes the signal while distributing a prescribed bit number for each frequency band based on the information from the bit distribute section 3 to generate the code series. The bit distribution section 3 receives information representing a block length from the block length decision section 1 to adopt a different audible psychological characteristic depending on the block length. |
