VOICE SIGNAL RECORDING METHOD, ITS TRANSMITTING METHOD, ITS RECORDING DEVICE, ITS TRANSMITTING DEVICE, ITS RECORDING MEDIUM AND ITS TRANSMITTING MEDIUM

摘要

PROBLEM TO BE SOLVED: To solve such a problem that a signal is instantaneous one which may be imperceivable for some person or in a case of some sound source since the signal in a level imperceivable as an original sound is singly added to a certain prescribed signal so that a sufficient effect to prevent copying is not obtained in a conventional manner. SOLUTION: A copy disturbing signal is generated by multiplying a making level by a level adjusting signalαwhich is set at each sub-band as a coefficient (step S13). The level adjusting signalαhas a numerical value being <=1 and a larger value is selected when a copy disturbance effect is preferential. The copy disturbance signal is added to the whole frequency band of the signal of an original frequency area (step S14). Then a copy preventing signal is added even to a band where an information amount in the original frequency area signal is not required. The frequency area signal after addition is performed is converted into the PCM signal of a time area, outputted (step S15) and recorded in a recording medium (step S16).