Abstract: In an audio signal processing procedure, auto-regressive (AR) modeling is used to create a residual signal from an input audio signal. The residual signal is further added to the input audio in order to produce a processed output audio signal. The AR modeling can be performed frame-by-frame or sample-by-sample employing frequency warped Burg's method.

Abstract: The invention relates to a system and method for detecting one or more gases or gas mixtures and/or for measuring the concentration of one or more gases or gas mixtures, said system comprising at least a light source, a sample space, a reference chamber, and a measuring chamber. The measuring chamber is supplied with a gas to be detected or measured. In addition, the measuring chamber is provided with a pressure sensor for detecting a photoacoustic signal generated in the measuring chamber. The pressure sensor comprises either a door, whose movement is measured without contact, or a sensor, whose movement is measured optically.

Abstract: The present invention relates to audio signal processing. According to the invention, auto-regressive (AR) modeling (10) is used to create a residual signal from an input audio signal. The residual signal is further added (30) to the input audio signal in order to produce a processed output audio signal.

Abstract: The present invention relates to an interferometer, comprising at least a beamsplitter (10), at least one end reflector (11) for returning beams (S2, S3), and a set of reflectors (14, 15) for reflecting the beams (S2, S3) between the beamsplitter (10) and the end reflector (11) or the end reflectors, at least some of said set of reflectors (14, 15) being adapted to be rotatable around an axis (?). Said set of reflectors comprises two angle reflectors (14, 15), constituted by plane reflectors, and the said end reflector (11) is or the end reflectors are an angle reflector constituted by plane reflectors (11?, 11?). An angle line of the end reflector (11) is or the angle lines of end reflectors are arranged perpendicular to an angle line of both of the angle reflectors (14, 15).