| 摘要 |
The present invention relates to an earphone protecting eardrums of a user, generating rich and smooth bass, and playing back sounds balanced from low to high notes. The earphone of the present invention, as an earphone used for playing sounds, comprises a housing; a speaker unit installed inside the housing; a penetration-hole formed at the housing to maintain pressure inside an ear to be equal to ambient atmospheric pressure outside the housing when the earphone is used, wherein a diameter of the penetration-hole is designed to be less than 0.4 when a length of the penetration-hole is 1 so that low-pitched sounds with a relatively long wave and broad amplitude among the played sounds can hardly pass through the penetration-hole, whereas air may pass through freely. |
