| 摘要 |
PROBLEM TO BE SOLVED: To prevent degradation of quality of an analog voice signal at the time of reproduction in the case of incorporating copyright data. SOLUTION: Copyright data are modulated by an FM modulator 114, an oscillator 115, a diffusion modulator 116, a diffusion code 117 and a level control section 118, and modulation data are applied to an adder 121 through a switch 210, and incorporated in digital voice data. A control section 200 detects variation of the level of digital voice data, and incorporates intermittently modulation data by controlling a copyright data supply section 100, a diffusion code 117, a switch 201 with control signals a, b, c respectively. |
