| 摘要 |
PURPOSE: To attain gain variation by digital signal processing with less sound quality deterioration by reducing production of noise sound in the case of gain change, conducting surely the gain revision processing and finishing the gain revision processing in a shortest required time. CONSTITUTION: A DSP 104 and a control section 109 are used to change a gain synchronously with a timing when a digital audio signal waveform being an object of gain revision is in crossing with an amplitude zero axis in terms of an AC signal and a timing in crossing with the amplitude zero axis in terms of an AC signal to update a coefft. for multiplication processing is monitored. A digital audio signal from the DSP 104 is converted into an analog audio signal and it is outputted through D/A converters 105a, 105b and LPFs 106a, 106b. |
