Abstract: A system and method for reducing noise in an audio signal. The system includes an encoder, a decoder and a single feedforward sidechain for generating a control signal that is used as input to a variable gain element in the encoder and in the decoder. The system is substantially audibly transparent, minimizes audible noise modulation, minimizes dynamic distortion of low frequency signals due to a level detector tracking these waveforms, minimizes distortion of signals due to phase shift in a transmission channel, minimizes distortion of fast, high-level transients due to the attack time of the level detector, and has virtually no effect on the audio signal if the level of the signal stays within a reasonable range around the nominal signal level.

Abstract: A method and apparatus for combining analog and digital processing techniques to thereby capture a much wider dynamic range of an original input signal than an A/D converter can by itself, to thereby preserve a maximum amount of information from the original input signal, wherein a processing amplifier combines a level-dependent, soft logarithmic limiting function with a high-frequency pre-emphasis filter, such that the pre-emphasis helps to compensate for a disproportionate reduction of high frequency information when portions of the signal are in an overload region, and wherein digital de-emphasis of the digitized signal enables recovery of the dynamic range that was sacrificed to create the overload region.

Abstract: This invention is concerned with lightpipes and lightpipe arrays designed to redirect light from a mounted light source, such as a light-emitting diode (LED), or from an array of mounted light sources. The lightpipe and lightpipe array are advantageously designed to be mounted to a surface not directly in contact with the light source(s) or the surface on which the light source(s) is (are) attached and to redirect light such that light exits the lightpipe at an elevation between the elevation of the light-emitting end of the light source and the elevation of the surface mounting such light source after a plurality of light reflections within a lightpipe(s). Several methods for attachment of the lightpipes to a mounting panel are described. A preferred embodiment of the invention features attachment of the lightpipe or lightpipe array to a mounting panel using a bezel or bezels which substantially prevent interference from stray light sources and prevent light from mixing between lightpipes of an array.