Voice mixing device, noise suppression method and program therefor

1. A voice mixing device for mixing a plurality of voice signals, comprising:

a speaker selection unit selecting at least one voice signal among said plurality of voice signals;

a full signal adder unit adding all of at least one voice signal selected by said speaker selection unit;

respective subtractor unit subtracting only one of said selected voice signals from an addition result of said full signal adder unit;

a common noise suppression unit suppressing noise of a common voice signal, being an addition result of said full signal adder unit;

individual noise suppression unit suppressing noise of respective individual voice signals, being subtraction results of said subtractor unit; and

memory switching unit copying information of noise suppression obtained in said common noise suppression unit based on a selection result of said speaker selection unit, to information of noise suppression in said individual noise suppression unit.

2. The voice mixing device according to claim 1 , further comprising a voice data switching unit switching and outputting a voice signal in which noise is suppressed, obtained by any one of said common noise suppression unit and said individual noise suppression unit, based on a selection result of said speaker selection unit.

3. The voice mixing device according to claim 1 , further comprising a preliminary noise suppression unit enabling selection as to whether or not to perform noise suppression on each of said plurality of voice signals.

4. The voice mixing device according to claim 1 , wherein said speaker selection unit selects said at least one voice signal based on power of said voice signal.

5. The voice mixing device according to claim 1 wherein said speaker selection unit selects said at least one voice signal based on whether said voice signal is voiced or unvoiced.

6. A multipoint conference system, comprising said voice mixing device according to claim 1 .

7. A noise suppression method used in a voice mixing device for mixing a plurality of voice signals, the method comprising:

selecting at least one voice signal among said plurality of voice signals, termed as a first step;

adding all of at least one voice signal selected in said first step, termed as a second step;

subtracting only one of said selected voice signals from an addition result of said second step, termed as a third step;

suppressing noise of a common voice signal, being an addition result of said second step, termed as a fourth step;

suppressing noise of an individual voice signal, being a subtraction result of said third step, termed as a fifth step; and

copying information of noise suppression obtained in said fourth step based on a selection result of said first step, to information of noise suppression of said fifth step, termed as a sixth step.

8. The noise suppression method according to claim 7 , further comprising switching and outputting a voice signal in which noise is suppressed, obtained in any one of said fourth step and said fifth step, based on a selection result of said first step, termed as a seventh step.

9. The noise suppression method according to claim 7 , further comprising selecting whether or not to perform noise suppression on each of said plurality of voice signals, before said first step, termed as an eighth step.

10. The noise suppression method according to claim 7 , wherein, in said first step, said at least one voice signal is selected based on power of said voice signal.

11. The noise suppression method according to claim 7 , wherein, in said first step, said at least one voice signal is selected based on whether said voice signal is voiced or unvoiced.