SIGNAL PROCESSING APPARATUS AND SIGNAL PROCESSING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a signal processing apparatus and method for amplifying audio signals at various levels to an appropriate level, and output of the amplified audio signals.

SOLUTION: The signal processing apparatus is equipped with: a PGA 132 for amplifying the level of an analog audio signal input from the outside with a PGA gain of which the magnitude is variable; an ADC 134 for converting the analog audio signal amplified by the PGA 132 into a digital audio signal; an audio adjusting filter processing section 140 for applying signal processing for audio quality adjustment to the digital audio signal; a first ALC 118 which detects the level of the digital audio signal prior to the signal processing and controls the magnitude of the PGA gain in accordance with the level detected; and a second ALC 120 which detects the level of the digital audio signal after the signal processing and amplifies the digital audio signal after the signal processing with an ALC gain determined in accordance with the detected level and the PGA gain controlled by the first ALC 118.

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