| 摘要 |
PURPOSE:To limit a sum within a range at the output side and to obtain an audibly excellent acoustic signal by applying compression conversion to a digital sum data of an acoustic signal outputted from a summing means based on the conversion characteristic which decreased its tilt as the absolute value is increased. CONSTITUTION:A digital sum data outputted from an adder 2 adding plural digital acoustic signals is subject to compression conversion based on the conversion characteristic in such a way that the tilt is decreased as the absolute value is increased. For example, when the absolute value of the digital summing data is a prescribed threshold level or below, the digital summing data is converted into a digital output data based on the conversion characteristic whose tilt is 1 and when the absolute value is a prescribed threshold level or over, the digital summing data is subject to compression conversion into a digital output data smaller than the value based on the conversion characteristic whose tilt is 1 or below. Thus, the digital output data is outputted to a D/A converter 11 with fidelity in a range where the absolute value of the amplitude with a high probability as the output of the digital summing data is small and the digital summing data is smoothly compressed in a range where the absolute value of the amplitude with a low output probability is large. |
