Voice sound input apparatus

1. A voice sound input apparatus, adapted to be inputted a sound and configured to output sound data, comprising: a display unit; a first microphone, related to a first sound hole; a second microphone, related to a second sound hole; a signal processing unit, configured to perform a signal processing based on at least one of outputs from the first microphone and the second microphone; and a microphone holding unit, formed in a rod shape, formed with the first sound hole, and adapted to extend toward a sound source predicted position located at a vertical direction of a display screen of the display unit, wherein a distance between the first sound hole and the second sound hole is set so that a strength ratio between a strength of differential sound pressure of sounds entered to the first sound hole and the second sound hole and a strength of sound pressure of the sound entered to the first sound hole with respect to phase components becomes smaller than the strength ratio with respect to amplitude components in a case that the sounds have a predetermined frequency range.

2. The voice input apparatus as claimed in claim 1 wherein the predetermined frequency range is a frequency range lower than or equal to 7 KHz.

3. A voice sound input apparatus, adapted to be inputted a sound and configured to output sound data, comprising: a display unit; a first microphone, related to a first sound hole; a second microphone, related to a second sound hole; a signal processing unit, configured to perform a signal processing based on at least one of outputs from the first microphone and the second microphone; and a microphone holding unit, formed in a rod shape, formed with the first sound hole, and adapted to extend toward a sound source predicted position located at a vertical direction of a display screen of the display unit; wherein the first microphone and the second microphone is located at a position where a distance between the first sound hole and the second sound hole is shorter than or equal to 8.1 mm.

4. The voice input apparatus according to claim 1 , wherein the microphone holding unit is detachably attached to a main body.

5. The voice input apparatus according to claim 4 , wherein: the signal processing unit includes a detecting unit configured to detect whether or not the microphone holding unit is attached to the main body; the signal processing unit is configured to perform the signal processing based on the output from the first microphone in a case that the detecting unit detects that the microphone holding unit is not attached to the main body; and the signal processing unit is configured to perform the signal processing based on the output from the first microphone and the output from the second microphone in a case that the detecting unit detects that the microphone holding unit is attached to the main body.

6. The voice input apparatus according to claim 1 , wherein: said microphone holding unit is formed with the second sound hole.

7. A voice sound input apparatus, adapted to be inputted a sound and configured to output sound data, comprising: a display unit; a first microphone, related to a first sound hole; a second microphone, related to a second sound hole; a signal processing unit, configured to perform a signal processing based on at least one of outputs from the first microphone and the second microphone; and a microphone holding unit, formed in a rod shape, formed with the first sound hole and the second sound hole, and adapted to extend toward a sound source predicted position located at a vertical direction of a display screen of the display unit; wherein: the signal processing unit includes a detecting unit configured to detect whether or not the microphone holding unit is attached to a main body; the signal processing unit is configured to perform the signal processing based on the output from the second microphone in a case that the detecting unit detects that the microphone holding unit is not attached to the main body; and the signal processing unit is configured to perform the signal processing based on the output from the first microphone and the output from the second microphone in a case that the detecting unit detects that the microphone holding unit is attached to the main body.

8. The voice input apparatus according to claim 1 , wherein a sectional area of the first sound hole is equal to a sectional area of the second sound hole.

9. The voice input apparatus according to claim 1 , wherein a volume of an internal space of the first sound hole is equal to a volume of an internal space of the second sound hole.

10. The voice input apparatus according to claim 1 , further comprising: a first vibration plate corresponding to the first microphone; and a second vibration plate corresponding to the second microphone, wherein a path length from an opening plane of the first sound hole to the first vibration plate is equal to a path length from an opening plane of the second sound hole to the second vibration plate.

11. The voice input apparatus according to claim 1 , wherein the signal processing unit is configured to generate a differential signal between an output signal of the first microphone and an output signal of the second microphone.

12. The voice sound input apparatus according to claim 1 , further comprising a vibration plate corresponding to both the first microphone and the second microphone, wherein a path length from an opening plane of the first sound hole to the vibration plate is equal to a path length from an opening plane of the second sound hole to the vibration plate.

13. The voice sound input apparatus according to claim 1 , wherein a sectional area of the first sound hole is larger than a sectional area of the second sound hole.

14. The voice sound input apparatus according to claim 1 , further comprising a mounting unit, configured to place the first sound hole at a position where a distance between the first sound hole and a sound source predicted position is shorter than or equal to 90 mm.

15. The voice sound input apparatus according to claim 1 , wherein the microphone holding unit is configured to adjust a distance between the first sound hole and a sound source predicted position due to at least one of pivotal movement, telescopic movement and deforming movement.

16. The voice sound input apparatus according to claim 1 , wherein the microphone holding unit is configured to adjust the distance between the first sound hole and the second sound hole.

17. The voice sound input apparatus according to claim 1 , wherein the microphone holding unit is configured to maintain the distance between the first sound hole and the second sound hole.

18. The voice sound input apparatus according to claim 1 , wherein the signal processing unit is configured to perform a beam forming processing in a predetermined angle range with reference to a predetermined direction.

19. The voice sound input apparatus according to claim 18 , wherein the signal processing unit includes a switching process unit configured to switch whether or not the beam forming processing is performed.

20. The voice sound input apparatus as claimed in claim 19 wherein: the signal processing unit includes a microphone sensitivity detecting unit configured to detect a sensitivity of at least one of the first microphone and the second microphone; and the signal processing unit is configured to switch whether or not the beam forming processing is performed based on a detection result of the microphone sensitivity detecting unit.

21. The voice sound input apparatus according to claim 18 , wherein the predetermined direction is a direction directed from the second sound hole to the first sound hole.