Abstract: Methods for calibrating active noise-cancelling headphones, including placing the active noise-cancelling headphones on a measuring device; exciting the active noise-cancelling filter; measuring one or more relevant transmission pathways selected from x(n), m(n), and p(n) for feedforward and/or h(n) for feedback; defining at least one goal function for feedforward or feedback; calculating a complementary function for the defined goal function for at least one branch of the active noise-cancelling filter; calculating an impulse response of the complementary function from the measurements of the relevant transmission pathways; approximating operating parameters for the active noise-cancelling filter using the Prony method; and implementing the approximated operating parameters in the active noise-cancelling filter on the signal processor in order to create an approximated complementary active noise-cancelling filter, thereby calibrating the active noise-cancelling headphones.

Abstract: Playback devices such as headphone devices can include an earpiece configured to be positioned adjacent a user's ear. The earpiece can include a transducer having a diaphragm configured to face toward the user's ear when the earpiece is positioned adjacent the user's ear, as well as an outlet vent in fluid communication with the transducer and a microphone. A support member within the earpiece includes a first opening aligned with the microphone and a second opening aligned with the outlet vent. An acoustic mesh extends over the first opening and the second opening, wherein the mesh has a substantially uniform acoustic impedance.

Abstract: Methods for calibrating active noise-cancelling headphones, including placing the active noise-cancelling headphones on a measuring device; exciting the active noise-cancelling filter; measuring one or more relevant transmission pathways selected from x(n), m(n), and p(n) for feedforward and/or h(n) for feedback; defining at least one goal function for feedforward or feedback; calculating a complementary function for the defined goal function for at least one branch of the active noise-cancelling filter; calculating an impulse response of the complementary function from the measurements of the relevant transmission pathways; approximating operating parameters for the active noise-cancelling filter using the Prony method; and implementing the approximated operating parameters in the active noise-cancelling filter on the signal processor in order to create an approximated complementary active noise-cancelling filter, thereby calibrating the active noise-cancelling headphones.

Abstract: Playback devices such as headphone devices can include an earpiece configured to be positioned adjacent a user's ear. The earpiece can include a transducer having a diaphragm configured to face toward the user's ear when the earpiece is positioned adjacent the user's ear, as well as an outlet vent in fluid communication with the transducer and a microphone. A support member within the earpiece includes a first opening aligned with the microphone and a second opening aligned with the outlet vent. An acoustic mesh extends over the first opening and the second opening, wherein the mesh has a substantially uniform acoustic impedance.

Abstract: In-ear active noise-cancelling (ANC) earphones for which the ANC circuit remains stable even under varying wearing conditions, the earphones being worn so that an eartip of the earphone is at least partially in the external auditory canal, with at least one speaker with a frontal volume leading to a tip area and/or speaker channel, and with at least one ANC microphone. To ensure that the ANC circuit remains stable even with a small available space, the earphones feature the connection of a frontal volume and/or a speaker channel with an additional volume via a tube ending in the tip area.

Abstract: In-ear active noise-cancelling (ANC) earphones for which the ANC circuit remains stable even under varying wearing conditions, the earphones being worn so that an eartip of the earphone is at least partially in the external auditory canal, with at least one speaker with a frontal volume leading to a tip area and/or speaker channel, and with at least one ANC microphone. To ensure that the ANC circuit remains stable even with a small available space, the earphones feature the connection of a frontal volume and/or a speaker channel with an additional volume via a tube ending in the tip area.

Abstract: An earphone is provided that can decrease a time delay between a microphone and a loudspeaker. The earphone includes a microphone incorporated with the membrane of loudspeaker. The loudspeaker and the microphone are connected by connection lines to an electronic circuit.

Abstract: A noise reducing sound reproduction system and method is disclosed, in which an input signal is supplied to a loudspeaker by which it is acoustically radiated. The signal radiated by the loudspeaker is received by a microphone that is acoustically coupled to the loudspeaker via a secondary path and that provides a microphone output signal. The microphone output signal may be subtracted from a useful-signal to generate a filter input signal. The filter input signal may be filtered in an active noise reduction filter to generate an error signal. The useful-signal may be subtracted from the error signal to generate the loudspeaker input signal, and the useful-signal may be filtered by one or more low-pass filters prior to subtraction from the microphone output signal.

Abstract: The invention relates to a plug earphone with a front portion and a rear portion, wherein a flexible plug can be placed on the front portion which includes an outer portion and an inner portion. An electroacoustic transducer is arranged in the rear portion, wherein the front portion is positioned on the electroacoustic transducer and on an opening of the rear portion produced in this area. To achieve a reliable acoustic friction piece which is easy to manufacture, the front portion, and optionally an inner portion and an outer portion, together with a front wall of the rear portion, forms at least one radial channel leading from the interior of the front portion to the outside, and an acoustic friction piece is optionally arranged in the radial channel.

Abstract: The invention relates to a plug earphone with a front portion and a rear portion, wherein a flexible plug can be placed on the front portion which includes an outer portion and an inner portion. An electroacoustic transducer is arranged in the rear portion, wherein the front portion is positioned on the electroacoustic transducer and on an opening of the rear portion produced in this area. To achieve a reliable acoustic friction piece which is easy to manufacture, the front portion, and optionally an inner portion and an outer portion, together with a front wall of the rear portion, forms at least one radial channel leading from the interior of the front portion to the outside, and an acoustic friction piece is optionally arranged in the radial channel.

Abstract: A system for actively reducing noise at a listening point, includes an earphone housing, a transmitting transducer, a receiving transducer and a controller. The transmitting transducer converts a first electric signal into a first acoustic signal, and radiates the first acoustic signal along a first acoustic path having a first transfer characteristic and along a second acoustic path having a second transfer characteristic. The receiving transducer converts the first acoustic signal and ambient noise into a second electrical signal. The controller compensates for the ambient noise by providing a noise reducing electrical signal to the transmitting transducer. The noise reducing electrical signal is derived from a filtered electrical signal that is provided by filtering the second electrical signal with a third transfer characteristic. The second and the third transfer characteristics together model the first transfer characteristic.

Abstract: An earphone is provided that can decrease a time delay between a microphone and a loudspeaker. The earphone includes a microphone incorporated with the membrane of loudspeaker. The loudspeaker and the microphone are connected by connection lines to an electronic circuit.

Abstract: A noise reducing sound reproduction system and method is disclosed, in which an input signal is supplied to a loudspeaker by which it is acoustically radiated. The signal radiated by the loudspeaker is received by a microphone that is acoustically coupled to the loudspeaker via a secondary path and that provides a microphone output signal. The microphone output signal may be subtracted from a useful-signal to generate a filter input signal. The filter input signal may be filtered in an active noise reduction filter to generate an error signal. The useful-signal may be subtracted from the error signal to generate the loudspeaker input signal, and the useful-signal may be filtered by one or more low-pass filters prior to subtraction from the microphone output signal.

Abstract: A system for actively reducing noise at a listening point, includes an earphone housing, a transmitting transducer, a receiving transducer and a controller. The transmitting transducer converts a first electric signal into a first acoustic signal, and radiates the first acoustic signal along a first acoustic path having a first transfer characteristic and along a second acoustic path having a second transfer characteristic. The receiving transducer converts the first acoustic signal and ambient noise into a second electrical signal. The controller compensates for the ambient noise by providing a noise reducing electrical signal to the transmitting transducer. The noise reducing electrical signal is derived from a filtered electrical signal that is provided by filtering the second electrical signal with a third transfer characteristic. The second and the third transfer characteristics together model the first transfer characteristic.