Pressure equalization in earphones

摘要

A headphone includes an electro-acoustic transducer dividing an enclosed volume into a front volume and a rear volume, a first port in the housing coupling the front volume to an ear canal of a user, a second port in the housing coupling the front volume to space outside the ear, a third port in the housing coupling the rear volume to space outside the ear, and an ear tip configured to surround the first port and including a flap to seal the ear canal from space outside the ear. The second port has a diameter and a length that provide an acoustic mass with an acoustic impedance with a high reactive component and a low resistive component, reducing the occlusion effect that otherwise results from sealing the ear.

主权项

1. A headphone comprising:
a housing defining an enclosed volume; an electro-acoustic transducer dividing the enclosed volume into a front volume and a rear volume; a first port in the housing arranged to couple the front volume to an ear canal of a user when the headphone is worn; a second port in the housing arranged to couple the front volume to space outside the ear of the user when the headphone is worn; a third port in the housing arranged to couple the rear volume to space outside the ear of the user when the headphone is worn; and an ear tip configured to surround the first port and including a flap to seal the ear canal from space outside the ear when the headphone is worn, the housing comprising an extended tab for retaining the ear tip; wherein the second port has a diameter and a length that provide an acoustic mass with an acoustic impedance with a high reactive component and a low resistive component, and an entrance to the first port is positioned next to a first side of the extended tab and an entrance to the second port is positioned next to a second side of the extended tab, such that the electro-acoustic transducer is approximately symmetrically loaded.