Acoustic output device

1. An earphone, comprising:

at least one low-frequency acoustic driver configured to output sounds from at least two first guiding holes, wherein the at least two first guiding holes include a near-ear first guiding hole closest to an ear hole of a user among the at least two first guiding holes and a far-ear first guiding hole that is farther from the ear hole of the user than the near-ear first guiding hole, and a ratio of an aperture of the near-ear first guiding hole to an aperture of the far-ear first guiding hole is not less than 1;

at least one high-frequency acoustic driver configured to output sounds from at least two second guiding holes, wherein the at least two second guiding holes include a near-ear second guiding hole closest to the ear hole of the user among the at least two second guiding holes, and a distance between the near-ear first guiding hole or the near-ear second guiding hole and the ear hole of the user is not larger than 2 cm; and

a controller configured to direct the low-frequency acoustic driver to output the sounds in a first frequency range and direct the high-frequency acoustic driver to output the sounds in a second frequency range, the second frequency range including one or more frequencies higher than one or more frequencies in the first frequency range.

2. The earphone of claim 1 , wherein distance between the near-ear first guiding hole or the near-ear second guiding hole and the ear hole of the user is not larger than 0.1 cm.

3. The earphone of claim 1 , wherein the at least two second guiding holes include a far-ear second guiding hole that is farther from the ear hole of the user than the near-ear second guiding hole, a ratio of an aperture of the near-ear second guiding hole to an aperture of the far-ear second guiding hole is not larger than 10.

4. The earphone of claim 1 , wherein a first distance is between the at least two first guiding holes, a second distance is between the at least two second guiding holes, the first distance is in a range of 20 millimeters-40 millimeters, and the second distance is in a range of 3 millimeters-7 millimeters.

5. The earphone of claim 4 , wherein the first distance is at least twice of the second distance.

6. The earphone of claim 1 , wherein

the first frequency range includes frequencies lower than 650 Hz, and the second frequency range includes frequencies higher than 1000 Hz.

7. The earphone of claim 1 , wherein the first frequency range overlaps with the second frequency range.

8. The earphone of claim 1 , wherein

the controller includes an electronic frequency division module configured to divide an audio source signal to generate a low-frequency signal corresponding to the first frequency range and a high-frequency signal corresponding to the second frequency range, the low-frequency signal driving the at least one low-frequency acoustic driver to generate the sounds, and the high-frequency signal driving the at least one high-frequency acoustic driver to generate the sounds.

9. The earphone of claim 8 , wherein the electronic frequency division module includes at least one of a passive filter, an active filter, an analog filter, or a digital filter.

10. The earphone of claim 1 , wherein

the at least one low-frequency acoustic driver includes a first transducer,

the at least one high-frequency acoustic driver includes a second transducer, and

the first transducer and the second transducer have different frequency response characteristics.

11. The earphone of claim 10 , wherein the first transducer includes a low-frequency loudspeaker, and the second transducer includes a high-frequency loudspeaker.

12. The earphone of claim 1 , wherein

at least two first acoustic routes are formed between the at least one low-frequency acoustic driver and the at least two first guiding holes,

at least two second acoustic routes are formed between the at least one high-frequency acoustic driver and the at least two second guiding holes, and

the at least two first acoustic routes and the at least two second acoustic routes have different frequency selection characteristics.

13. The earphone of claim 12 , wherein each of the at least two first acoustic routes includes an acoustic resistance material, and an acoustic impedance of the acoustic resistance material is in a range from 5MKS Rayleigh to 500MKS Rayleigh.

14. The earphone of claim 1 , further comprising:

a supporting structure configured to support the at least one high-frequency acoustic driver and the at least one low-frequency acoustic driver, and keep the at least two first guiding holes and the at least two second guiding holes away from a user's ear.

15. The earphone of claim 14 , wherein the at least two first guiding holes and the at least two second guiding holes are disposed on the supporting structure.

16. The earphone of claim 14 , wherein the supporting structure includes a first housing, the low-frequency acoustic driver is encapsulated by the first housing, and the first housing defines a front chamber and a rear chamber of the low-frequency acoustic driver.

17. The earphone of claim 16 , wherein the front chamber of the low-frequency acoustic driver is acoustically coupled to one of the at least two first guiding holes, and the rear chamber is acoustically coupled to the other first guiding hole of the at least two first guiding holes.

18. The earphone of claim 14 , wherein the supporting structure includes a second housing, the high-frequency acoustic driver is encapsulated by the second housing, and the second housing defines a front chamber and a rear chamber of the high-frequency acoustic driver.

19. The earphone of claim 1 , wherein the sounds output from the at least two first guiding holes have opposite phases.