| 摘要 |
PURPOSE:To eliminate an error in voice sound/silent sound discrimination due to sounds other than human voice, to allow a receiver side to always add noise and to eliminate a sense of unnaturality by dividing a digital voice signal into plural frequency bands to detect power. CONSTITUTION:Detection sections 31-34,4 detect a power and a zero cross point of a digital voice signal, discrimination sections 51-55 discriminate the voice sound/silent sound based on the detection, the voice signal is coded by a coder 2 according to a transmission rate based on the result of discrimination and the coded voice signal and the performance of the voice sound/silent sound are sent by the voice signal transmission system. Then the digital voice signal is divided into plural frequency bands, from which power is detected. Furthermore, since the voice frequency is distributed to be 2kHz or below, the power detection result for the band is taken as priority. On the other hand, a receiver side adds noise regardless of the voice sound/unvoice sound. Thus, as to the sender side, mis-discrimination of the voice sound due to background noise is avoided and noise is always applied at the receiver side, then the unnaturality of the border of the voice sound/silent sound is eliminated. |
