Electronic device for microphone operation

1. An electronic device, comprising:

a first microphone unit installed in a front side of the electronic device;

a second microphone unit installed in a back side of the electronic device;

a third microphone unit installed at a position within the electronic device;

at least one sensor installed in the electronic device, for sensing a usage condition of the electronic device; and

a processor for selectively activating at least two of the first, second and third microphone units in response to the sensed usage condition of the electronic device,

wherein the electronic device is a portable terminal for performing a communication function, and

wherein the usage condition indicates at least one of an angle between the electronic device and a floor surface, and whether a side of the electronic device comes in contact with the floor surface.

2. The electronic device of claim 1 , wherein the third microphone unit is located at a lateral side of the electronic device.

3. The electronic device of claim 1 , wherein the third microphone unit is located at a boundary portion between the front side and a lateral side of the electronic device.

4. The electronic device of claim 1 , wherein the third microphone unit is located at a boundary portion between the back side and a lateral side of the electronic device.

5. The electronic device of claim 1 , wherein the at least one sensor comprises proximity sensors which are installed in the front side and the back side of the electronic device, respectively, for sensing whether the front side or the back side comes in contact with the floor surface.

6. The electronic device of claim 1 , wherein the at least one sensor comprises camera modules which are installed in the front side and the back side of the electronic device, respectively, for sensing whether the front side or the back side comes in contact with the floor surface.

7. The electronic device of claim 1 , wherein the at least one sensor comprises illumination sensors, which are installed in the front side and the back side of the electronic device, respectively, for sensing whether the front side or the back side comes in contact with the floor surface.

8. The electronic device of claim 1 , wherein the at least one sensor comprises at least one of, a gyro sensor and an acceleration sensor, which are installed in the electronic device, for sensing the angle.

9. The electronic device of claim 1 , wherein the processor inactivates at least one of the first and second microphone units located at the side of the electronic device which comes in contact with the floor surface in response to the at least one sensor sensing that the electronic device resides on the floor surface.

10. The electronic device of claim 1 , wherein the processor activates at least one of the first and second microphone units and the third microphone unit when the at least one sensor senses that the electronic device is orientated at an angular range relative to the floor surface.

11. The electronic device of claim 10 , wherein the angular range is a range where the electronic device has an angle of −30 degrees to 30 degrees relative to the floor surface.

12. The electronic device of claim 1 , wherein the first microphone unit is located at a front upper end portion of the electronic device and wherein the second microphone unit is located at the back side of a portion where it is overlapped with the first microphone unit or a portion adjacent to an overlapped position.

13. The electronic device of claim 12 , wherein the second microphone unit is located within an overlap region comprising a range of 1 cm to 5 cm from a center of the first microphone unit in the back side of the electronic device.

14. An operation method of an electronic device, the operation method comprising:

determining a current usage condition of the electronic device comprising a physical orientation of the electronic device relative to a surface in response to sensing by at least one sensor installed in the electronic device; and

selectively activating two of first, second and third microphone units and inactivating the remaining microphone unit of the first, second and third microphone units, in response to the determined usage condition,

wherein the first, second and third microphone units are located at front, back, and lateral sides of the electronic device,

wherein the electronic device is a portable terminal for performing a communication function, and

wherein the usage condition indicates at least one of an angle between the electronic device and a floor surface, and whether a side of the electronic device comes in contact with the floor surface.

15. The operation method of claim 14 , further comprising inactivating at least one of the first, second and third microphone units, which is installed in the side of the electronic device facing the floor surface when the at least one sensor senses that the electronic device is laid on the floor surface.

16. The operation method of claim 15 , wherein the at least one sensor comprises at least one of proximity sensors, illumination sensors, and camera modules, which sense that the electronic device is laid on the floor surface.

17. The operation method of claim 14 , further comprising activating one of the first and second and third microphone units when the at least one sensor senses that the electronic device is orientated within an angular range relative to the floor surface.

18. The operation method of claim 17 , wherein the angular range comprises −30 degrees to 30 degrees relative to the floor surface.

19. The operation method of claim 14 , wherein the at least one sensor is a gyro sensor for sensing the angle.