Earphone with an acoustic rear chamber vent

An earphone configured to provide an acoustic output to an ear of a wearer and further configured to be arranged on the wearer's head in an operating position such that a front chamber between the head and the earphone is separated from ambient space, the earphone comprising:

• a housing having a housing wall separating a rear chamber from ambient space, the housing wall including a dividing wall separating the rear chamber from the front chamber,
• a diaphragm suspended across an opening in the dividing wall and configured to be actively driven to provide the acoustic output,
• a vent structure fluidly connecting the rear chamber and ambient space through the housing wall,
• wherein the vent structure comprising
• a longitudinal recess in the housing wall, which recess is defined by a bottom wall and recess walls connecting the bottom wall and the housing wall,
• a recess opening in the recess, which recess opening connects the recess and the rear chamber,
• a mesh device arranged parallel with the bottom wall, whereby a longitudinal recess cavity is provided between the bottom wall and the mesh structure,
• wherein the earphone comprises a unitary earphone element comprising an end wall and a side wall, and wherein the recess is provided in the end wall, and wherein the earphone element is shaped, such it can be manufactured in an injection mould without overhangs.