Patent ID: 6490361
Filing Date: 2002-12-03
Classification: H04M,H04R

Abstract:
An apparatus having a housing bounding an inner housing space and having a housing wall provided with sound transmission openings, said apparatus being applicable to an ear of a user in an area of the sound transmission openings in an on-ear mode of the apparatus, said apparatus further having an elecroacoustic transducer accommodated in the inner housing space and arranged adjacent to the sound transmission openings, said electroacoustic transducer having a front volume and a rear volume and being capable of generating sound for emission into the acoustic free space via the front volume and through the sound transmission openings, the rear volume being open to the inner housing space, and said apparatus further having at least one passage traversing a housing wall and forming, together with the inner housing space and the rear volume of the electroacoustic transducer, an absorption-circuit resonator which causes a dip in the sound pressure versus frequency response when the apparatus operates in the on-ear mode, and said apparatus further having compensation means for compensation of the dip in the sound pressure versus frequency response, characterized in that said compensation means comprises at least one duct traversing the housing and being arranged outside the wall portion covered by an ear in the on-ear mode and adjacent to the rear volume of the electroacoustic transducer, said at least one duct forming an acoustic friction.