Abstract: An unknown transmission function comprising an input signal (x) and an actual output signal (y) is estimated. An estimated output signal (y) is generated by adaptive process (2) using the input signal (x), an error signal (e) is generated from the actual output signal (y) and the estimated output signal (y), and the adaptive process (2) is improved based on the error signal (e), at least one signal path, i.e. a signal path conducting the error signal or a signal path conducting the estimated output signal (y), being impinged upon by a predefined signal in accordance with at least one condition. This makes it possible to substantially optimize adaptive processes or algorithms. Also disclosed are an application of the method, a device, and a use of the device.

Abstract: An apparatus and method for compensating for changes, which result on an original signal (17) due to a transmission along a signal path (2, 3, 4, 7) from a source (1) to a receiving listener (5) involve compensating the changes in the original signal occurring in the signal path (2, 3, 4, 7) by minimizing differences between the original signal (17) and a reproduced signal, which is perceived by the receiving listener (5). This makes it possible for the receiving listener (5) to perceive the originally recorded original signal (17).

Abstract: Disclosed in a method in which a digital system is used for actively reducing noise. According to the method, a digital user signal can be transmitted at a different sampling rate, the sampling rate being adjusted with the aid of adequate converters.

Abstract: In active noise reduction, at least one input signal (25) is fed to a computing unit (18), which passes on the at least one input signal (25) to at least one additional computing unit (19), wherein the at least one input signal (25) is processed for the generation of at least one output signal (26) in the at least one additional computing unit (19). Therein, a kind of processing for processing in the additional computing unit (19) is set by the computing unit (18). Finally, the generated at least one output signal (26) is fed to the computing unit (18). Furthermore, apparatuses for carrying out the method are disclosed.

Abstract: Method and apparatus for determining a position and/or movement of a first part (1) relative to a second part in an electroacoustic transducer to which a signal for conversion is supplied. The method involves the first part (1) being irradiated with beams produced by a radiation source (12, 13), where the radiation source (12, 13) is rigidly connected to the second part, at least some of the beams produced by the radiation source (12, 13) being altered by the first part (1), at least some of the beams altered by the first part (1) being measured using a reception unit (14, 16), and the beams measured in the reception unit (14, 16) being taken as a basis for calculating the position and/or the movement of the first part (1) relative to the second part.

Abstract: A method of estimating an unknown transfer function (H) which comprises an input signal (x) and an actual output signal (y), wherein an estimated output signal (?) is generated in an adaptive process (3) using the input signal (x). An error signal (?) is generated from the actual output signal (y) and the estimated output signal (?) and the error signal (?) is used to improve the adaptive process (3), whereby at least one of the following signal paths is interrupted or opened depending on at least one condition: a signal path carrying the error signal (?), a signal path carrying the input signal (x), or a signal path carrying the estimated output signal (?). The method allows substantially stabilizing adaptive processes or algorithms. The disclosed method and device for carrying out the method are useful for active noise reduction in a room.

Abstract: A method for reproducing a secondary path in an active noise reduction system comprising a transmission path (S, 9?, 10, 11), an adaptively adjustable filter (13), and an addition unit (14), the adaptively adjustable filter (13) being adjusted according to an output signal of the addition unit (14). A delay time (T) of a signal along the transmission path (8, 9, 10, 11) is eliminated in the transmission function of the adaptively adjustable filter (13) in order to generate the reproduction of the secondary path.

Abstract: Disclosed is an active noise detection system which is used in a room and utilizes at least one sensor unit for detecting the residual cumulative signal (e+g), one of the sensor units being used for detecting a useful signal (g). In order to make said useful signal (g) available at an improved quality, an additional adaptive process unit (11) is provided which controls another filter unit (10) so as to eliminate the residual signal (e) from the previously detected cumulative signal (e+g), thus making it possible to obtain the useful signal (g) that largely corresponds to the effective useful signal.

Abstract: A method for monitoring a room (R) is specified, in which acoustic properties ({circle around (S)}, W) of the room (R) are determined, changes (?) in the acoustic properties ({circle around (S)}, W) of the room (R) are detected, the changes (?) are compared with prescribed criteria (?{circle around (S)}, ?W)and an action (?) is triggered if the prescribed criteria (?{circle around (S)}, ?W) have been satisfied. This makes it possible to monitor a room with the aid of an active noise reduction system. If there is no need to monitor a room, the system can be used for active noise reduction.