A headphone comprising: an acoustic transducer having a sound-radiating surface generally in a plane; a housing (113, 115) enclosing the acoustic transducer; a first acoustic chamber defined by a first side of the acoustic transducer and a first portion of the housing, the first acoustic chamber including a first reactive port and a first resistive port in a parallel configuration to couple the first acoustic chamber with space outside the headphone; a second acoustic chamber defined by a second side of the acoustic transducer and a second portion of the housing, the second acoustic chamber separated from the first acoustic chamber by the acoustic transducer; the headphone being characterized in that it further comprises: a nozzle having an opening coupling the second acoustic chamber to the wearer's ear canal and extending a part of the second acoustic chamber into the ear canal in a direction that is substantially parallel to the plane of the sound-radiating surface of the transducer; wherein an acoustically resistive element is located in the opening of the nozzle, and wherein the acoustically resistive element includes a hole therethrough, the hole being arranged so as to provide damping of higher frequency resonances while having more low frequency output compared to an acoustically resistive element without a hole. an acoustic transducer having a sound-radiating surface generally in a plane; a housing (113, 115) enclosing the acoustic transducer; a first acoustic chamber defined by a first side of the acoustic transducer and a first portion of the housing, the first acoustic chamber including a first reactive port and a first resistive port in a parallel configuration to couple the first acoustic chamber with space outside the headphone; a second acoustic chamber defined by a second side of the acoustic transducer and a second portion of the housing, the second acoustic chamber separated from the first acoustic chamber by the acoustic transducer; the headphone being characterized in that it further comprises: a nozzle having an opening coupling the second acoustic chamber to the wearer's ear canal and extending a part of the second acoustic chamber into the ear canal in a direction that is substantially parallel to the plane of the sound-radiating surface of the transducer; wherein an acoustically resistive element is located in the opening of the nozzle, and wherein the acoustically resistive element includes a hole therethrough, the hole being arranged so as to provide damping of higher frequency resonances while having more low frequency output compared to an acoustically resistive element without a hole. a nozzle having an opening coupling the second acoustic chamber to the wearer's ear canal and extending a part of the second acoustic chamber into the ear canal in a direction that is substantially parallel to the plane of the sound-radiating surface of the transducer; wherein an acoustically resistive element is located in the opening of the nozzle, and wherein the acoustically resistive element includes a hole therethrough, the hole being arranged so as to provide damping of higher frequency resonances while having more low frequency output compared to an acoustically resistive element without a hole.