Earphone

1. An earphone comprising:

a loudspeaker unit configured to generate sound waves;

a sound conduit tube connected to the loudspeaker unit; and

an ear tip connected to the sound conduit tube, and having a shape that has at least one opening, wherein

the sound conduit tube has a shape that has:

a sound hole having a first opening through which the sound waves generated by the loudspeaker unit enter, and a second opening from which the sound waves are released and to which the ear tip is connected; and

a vent hole formed independently of the sound hole, and having a third opening through which a portion of the sound waves released from the second opening enters and a fourth opening from which the portion of the sound waves is released outside the earphone, and

the second opening of the sound hole and the third opening of the vent hole are connected to an identical opening of the ear tip,

wherein an opening size of the fourth opening of the vent hole is adjusted by parallelly moving the ear tip along the sound conduit tube.

2. The earphone according to claim 1 , wherein

the loudspeaker unit has a shape that has:

a first sound hole from which sound waves are released to the sound conduit tube; and

a second sound hole from which sound waves having an opposite phase of the sound waves released from the first sound hole are released, and

opening sizes of the fourth opening and the second sound hole are simultaneously adjusted by parallelly moving the ear tip along the sound conduit tube.

3. The earphone according to claim 2 , wherein adjustment is made such that the fourth opening and the second sound hole are both blocked.

4. The earphone according to claim 1 , wherein

the loudspeaker unit has a shape that has:

a first sound hole from which sound waves are released to the sound conduit tube; and

a second sound hole from which sound waves having an opposite phase of the sound waves released from the first sound hole are released,

the loudspeaker unit includes a cover having formed thereon holes corresponding to the first sound hole and the second sound hole, and

opening sizes of the fourth opening and the second sound hole are simultaneously adjusted by parallelly moving the cover along the loudspeaker unit.

5. The earphone according to claim 4 , wherein adjustment is made such that the fourth opening and the second sound hole are both blocked.

6. The earphone according to claim 1 , wherein a magnetic fluid is used in the loudspeaker unit.

7. A hearing aid comprising the earphone according to claim 1 .

8. A headset comprising the earphone according to claim 1 .

9. The earphone according to claim 1 , wherein the fourth opening of the vent hole is formed at a location that is not blocked simultaneously with the third opening.

10. The earphone according to claim 1 , wherein the sound hole is formed at a center of the sound conduit tube, and the vent hole is formed independently of the sound hole at an outer circumference thereof.

11. The earphone according to claim 1 , wherein the vent hole is formed at a center of the sound conduit tube, and the sound hole is formed independently of the vent hole at an outer circumference thereof.

12. An earphone comprising:

a loudspeaker unit configured to generate sound waves;

a sound conduit tube connected to the loudspeaker unit; and

an ear tip connected to the sound conduit tube, and having a shape that has at least one opening, wherein

the sound conduit tube has a shape that has:

a sound hole having a first opening through which the sound waves generated by the loudspeaker unit enter, and a second opening from which the sound waves are released and to which the ear tip is connected; and

a vent hole formed independently of the sound hole, and having a third opening through which a portion of the sound waves released from the second opening enters and a fourth opening from which the portion of the sound waves is released outside the earphone, and

the second opening of the sound hole and the third opening of the vent hole are connected to an identical opening of the ear tip,

wherein an opening size of the third opening of the vent hole is adjusted by rotationally moving the ear tip around the sound conduit tube.

13. The earphone according to claim 12 , wherein

the loudspeaker unit has a shape that has:

a first sound hole from which sound waves are released to the sound conduit tube; and

a second sound hole from which sound waves having an opposite phase of the sound waves released from the first sound hole are released, and

opening sizes of the third opening and the second sound hole are simultaneously adjusted by rotationally moving the ear tip around the sound conduit tube.

14. The earphone according to claim 13 , wherein adjustment is made such that the third opening and the second sound hole are both blocked.

15. The earphone according to claim 12 , wherein a magnetic fluid is used in the loudspeaker unit.

16. A hearing aid comprising the earphone according to claim 12 .

17. A headset comprising the earphone according to claim 12 .

18. The earphone according to claim 12 , wherein the fourth opening of the vent hole is formed at a location that is not blocked simultaneously with the third opening.

19. The earphone according to claim 12 , wherein the sound hole is formed at a center of the sound conduit tube, and the vent hole is formed independently of the sound hole at an outer circumference thereof.

20. The earphone according to claim 12 , wherein the vent hole is formed at a center of the sound conduit tube, and the sound hole is formed independently of the vent hole at an outer circumference thereof.