Noise reducing sound-reproduction

An active noise reduction system comprising:

• an earphone to be acoustically coupled to a listener's ear which is exposed to ambient noise, the earphone comprises
• a housing with an aperture;
• a transmitting transducer which converts electrical signals into acoustical signals to be radiated to the listener's ear and which is arranged at the aperture of the housing thereby defining an earphone cavity located behind the transmitting transducer;
• and
• a receiving transducer which converts acoustical signals into electrical signals and provides a receiving-transducer signal indicative thereof, and which is arranged behind, alongside or in front of the transmitting transducer;
• a sound-guiding conduit having a first longitudinal end and a second longitudinal end, where the first longitudinal end is acoustically coupled to the receiving transducer and the second longitudinal end is located behind, alongside or in front of the transmitting transducer;
• a first acoustical path which extends from the transmitting transducer to the ear and which has a first transfer characteristic;
• a second acoustical path which extends from the transmitting transducer through the sound-guiding conduit to the receiving transducer and which has a second transfer characteristic;
• and
• a control unit electrically connected to the receiving transducer and the transmitting transducer and which compensates for the ambient noise at the ear by generating a noise reducing electrical signal supplied to the transmitting transducer,
• where the noise reducing electrical signal is derived from the receiving-transducer signal filtered with a third transfer characteristic, and
• where the second and third transfer characteristics together model the first transfer characteristic.