| 摘要 |
PURPOSE:To improve the performance of an echo device which increasing the dynamic range of the voice signal from a microphone. CONSTITUTION:In front of an echo digital signal processing circuit 4 which generates an echo component, a square root circuit 7 compresses the level of the voice signal and behind a mixing amplifier 5, a squaring circuit 8 expands the voice signal. Consequently, the dynamic range of the voice signal from the microphone 1 can be raised and the voice signal inputted to the echo digital signal processing circuit 4 is prevented from being distorted by getting saturated. |
