| 摘要 |
PROBLEM TO BE SOLVED: To obtain the reproducing signals having a good S/N ratio even though voice signals having any frequency bands are inputted. SOLUTION: The device is provided with an input signal analyzer 2, which analyzes the frequency characteristic of inputted voices, a differencing circuit 1, which conducts a differential pulse code modulation(DPCM) differencing operation based on any one of the plural compressing characteristics (difference equations), and a difference equation controller 3 which selectively switches any one of the difference equations based on the analysis result of the inputted voices. By analyzing the frequency characteristic of the inputted voices and selectively switching the difference equations, that are used in the circuit 1, based on the analysis result, a most suitable difference equation is selected in accordance with the frequency band of the inputted voices and a voice compression is conducted accordingly. |
