| 摘要 |
PROBLEM TO BE SOLVED: To insert copyright management information into an audio signal. SOLUTION: An audio signal processing apparatus for inserting a payload signal into a primary audio signal is equipped with a noise generator for generating a noise signal based on the payload signal, a level detector for detecting the signal level of the primary audio signal, a modulator for generating the noise signal modulated by increasing or decreasing the noise level according to the increase or decrease of the detected signal level of the primary audio signal, a coupler for coupling the primary audio signal and the modulated noise signal, and a signal delay circuit. The modulator operates in relation to the signal delay circuit to advance the decrease of the level of the noise signal in time with respect to the corresponding decrease of the signal level of the primary audio signal. COPYRIGHT: (C)2007,JPO&INPIT
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