Abstract: A device is provided for reducing noise in the human ear having a microphone which picks up the noise and a reproduction transducer to which a noise compensation signal is fed via a compensation circuit which is connected with the microphone. The microphone in the device has a balancing element which is arranged in front of the sound entrance opening of the microphone. The balancing element defines a quasi-constant sound reflection and accordingly reduces individual reflection effects caused by the fundamental diversity of the external region of the human ear and improves the use of the entire device and increases the effectiveness of the noise compensation overall. In this way, headphones/hearing protectors can also be designed as acoustically closed systems which are designed so as to rest on the ear.

Abstract: A sound reproduction device such as a headphone with active noise compensation has a housing and a transducer for converting electrical signals to sound waves is disposed within the housing. The transducer has a diaphragm for separating the volume (V.sub.2) in front of the diaphragm from the volume (V.sub.1) to the rear of the diaphragm. The transducer diaphragm and rear volume (V.sub.1) have a determined compliance. The sound reproduction device includes active noise compensation components for reducing unwanted noise at the output of the transducer. The diaphragm has a compliance (N.sub.M) which is less than the compliance (N.sub.1) of the rear volume (V.sub.1). The diaphragm is preferably constructed from a plurality of layers. In a further preferred arrangement, a damping element is disposed very close to the rear side of the diaphragm. A preferred construction for optimizing the voice coil is described.

Abstract: A sound reproduction device such as a headphone with active noise compensation has a housing and a transducer for converting electrical signals to sound waves is disposed within the housing. The transducer has a diaphragm for separating the volume (V.sub.2) in front of the diaphragm from the volume (V.sub.1) to the rear of the diaphragm. The transducer diaphragm and rear volume (V.sub.1) have a determined compliance. The sound reproduction device includes active noise compensation components for reducing unwanted noise at the output of the transducer. The diaphragm has a compliance (N.sub.M) which is less than the compliance (N.sub.1) of the rear volume (V.sub.1). The diaphragm is preferably constructed from a plurality of layers. In a further preferred arrangement, a damping element is disposed very close to the rear side of the diaphragm. A preferred construction for optimizing the voice coil is described.

Abstract: Infrared light is used in a device for wireless transmission of digital data, e.g. in headphones. In order to satisfy the strict requirements regarding compactness and power consumption, it is proposed that three digital stereo sampling values are encoded in data frames of 128-bit length for channel coding. Control characteristics and synchronizing characteristics are added to these data frames. A special coding rule is used for the sampling value coding.

Abstract: An electrodynamic transducer has a diaphragm substantially having two parts with different profiles, namely an acoustically active central part and an annular part laterally adjoining the central part and serving for the resilient suspension of the diaphragm in its entirety. A narrow coil seat for a wire coil of the transducer is located between the central part and the annular part. For the purpose of developing a compact yet electrodynamically sensitive acoustic transducer, the annular part is not arranged radially outside the central part of the diaphragm, but is shifted inward according to the invention. The curved annular part is thus accommodated under the axial curvature of the central part. The annular part can therefore have the annular width required for an ideal resilient suspension without negatively affecting the outer dimensions of the transducer.

Abstract: Capacitive sound transducer of a very small construction, in particular a microphone has at least two joint semiconductor chips, which embody a membrane unit and a fixed counter-electrode structure. The acoustic active portion of the membrane unit 1 with at least one counter-electrode structure 3, which is separated from the membrane unit by means of an air gap, forms a system which is comparable to a field effect transistor. The membrane unit which is formed of a semiconducting ground material encompasses an acoustically active membrane surface (2), one side 5 of which confronts the counter-electrode structure is electrically conductive.The counter-electrode structure 3 has a semiconductive base material out of which there is machined a channel length which has been limited by a source-drain arrangement, the geometric width measurrement of which is on the order of magnitude of a tenth of the lateral measurement of the active membrane surface.

Abstract: An infrared headphone with supplemental microphones to aid the hearing impaired allowing the user to hear the significant sounds from the ambient surroundings. In order to suppress the sound intensity of the user's own voice the invention provides for microphones arranged at a distance from each other on a supporting elbow in such a way that when they are mounted on the head of the user they are symmetrically arranged with respect to a median plane of the user's head and the signals emitted from the microphones are conducted in counter-phase with respect to each other.