| 摘要 |
A system for descriminating a human voice signal from other sounds comprises a mixer 24 having two input channels and connected to a high pass filter 25 for removing subsonic sounds below 20 HZ. The output of the filter 25 is connected through a low pass filter 3 to the input of a voltage controlled variable gain amplifier 4, the output of which is connected to a body-felt vibration generator. The output of filter 25 is also connected through an equalizer 26 and a signal level compressor 27 to the inputs of a double bass sound region deriving circuit 28, a level detector 8, and a human voice fundamental wave emphasizing and deriving circuit 9. The double bass circuit 8 includes a low pass filter having a cut-off frequency of 60 Hz. The circuit 9 derives the fundamental human voice sound wave by regarding the human voice as an amplitude modulated wave with the fundamental waves generated in the vocal cords being regarded as the modulating waves and the formants imposed during passage through the vocal tubes as the carrier wave. The circuit 9 includes a detector and a band pass filter. The outputs of the circuits 28, 8 and 9 are connected to the inputs of an arithmetic circuit 10, the output of which is connected to the control terminal of the amplifier 4. In use, the amplifier 4 suppresses double bass signals originating from a human voice but passes other double-bass signals. <IMAGE> |
