| 摘要 |
An apparatus for frequency band reduction of a voice signal having an upper and lower band limit including a voice signal input. A clipping circuit (2) clips the positive and negative peaks of the voice signal connected to the voice signal input. A bandpass filter (3) is connected to the clipping circuit for rejecting harmonics created by the clipping circuit. A low and high end roll-off filter device is provided for producing a given db/octave frequency roll off at the lower bandlimit. The geometric mean value of the upper and lower bandlimit falls within a given lower and a given upper frequency range. |
