An in-ear earphone has a housing in which a driver is located. An articulated acoustic tube is coupled to the housing at its near end portion. The acoustic tube has an open far end portion that is to be inserted into an ear. A hinge or pivot mechanism is formed in the tube, between the near and far end portions. An acoustic aperture formed within the mechanism acoustically couples sound pressure waves, generated by the driver, to the far end portion of the acoustic tube. Other embodiments are also described.