| 摘要 |
PROBLEM TO BE SOLVED: To minimize deterioration of audio quality so as to make it possible to superimpose additional information even if an audio signal is an analog audio signal by providing, in a specific period of the audio signal, an short break period having such a time length that it is difficult to be heard as a click sound and superimposing the additional information on an analog audio information using the short break period. SOLUTION: An attack detection unit 11 detects as an attack a portion of an input analog audio signal which rapidly rises and has a large amplitude, and supplies this detected timing to a microcomputer 13 as an output. The microcomputer 13 monitors whether or not the attack detection unit 11 detects the attack portion in the input analog audio signal. A spectrum analysis unit 12 analyzes the input analog signal to supply detection result of a wide frequency range distribution of the audio signal to the microcomputer 13. A switch circuit 15 for generating a short break period is controlled by the microcomputer 13 to obtain an audio signal Sol having the instant pause period generated in such a period that has an audio signal component in the wide band. |
