Patent ID: 6628790
Filing Date: 2003-09-30
Classification: H04R

Abstract:
An apparatus (1)which is adapted to emit sound, and which is adapted to be used in an on-ear mode and in an off-ear mode, and which has a housing (2) having housing walls, and which includes a holder compartment (6) which is accommodated in the housing (2) and which is bounded by a bounding wall (7) formed with at least one internal sound port (10, 11), and which has an outer wall (3) which is spaced at a distance from the bounding wall (7) and which together with the bounding wall (7) bounds an intermediate space (14) and has at least one external sound port (15, 16) which during use of the apparatus (1) in the on-ear mode by a user is to be held so as to face the inner part of the auricle of the user, and which has at least one additional external sound port (19) between the bounding wall (7) and the outer wall (3), through which port the sound waves can emerge in directions substantially parallel to the bounding wall (7) and to the outer wall (3), and which includes an electroacoustic transducer (20) for the generation of sound, which transducer is accommodated in the holder compartment (6) and can generate sound waves which can be emitted through the at least one internal sound port (10, 11) into the intermediate space (14) and from the intermediate space (14) through the at least one external sound port (15, 16) and through the at least one additional external sound port (19), and which includes at least one signal source (30, 35) adapted to drive the electroacoustic transducer (20) with at least one useful signal, characterized in that the bounding wall (6) has at least one additional internal sound port (22), and the holder compartment (6) accommodates a second electroacoustic transducer (25) for the generation of sound, by means of which second electroacoustic transducer sound waves can be generated which can be emitted through the at least one additional internal sound port (22), and application means (38) have been provided with the aid of which a useful signal to be applied to the first transducer (20) can always be applied to the first transducer (20) in a first phase relationship and with the aid of which a useful signal to be applied to the second transducer (25) can also be applied to the second transducer (25) in a first phase relationship but, in additional, also in a second phase relationship opposite to the first phase relationship, and control means (41) have been provided which ensure that in the off-ear mode a useful signal is applied to the second transducer (25) in the first phase relationship and in the on-ear mode a useful signal is applied to the second transducer (25) in the second phase relationship.