Patent ID: 8588427
Filing Date: 2013-11-19
Classification: H04R

Abstract:
1. An apparatus for extracting an ambient signal on the basis of a time-frequency-domain representation of an input audio signal, the time-frequency-domain representation representing the input audio signal in terms of a plurality of sub-band signals describing a plurality of frequency bands, the apparatus comprising: a gain-value determinator configured to determine a sequence of time-varying ambient signal gain-values for a given frequency band of the time-frequency-domain representation of the input audio signal in dependence on the input audio signal; a weighter configured to weight one of the sub-band signals representing the given frequency band of the time-frequency-domain representation with the gain-values, to obtain a weighted sub-band signal; wherein the gain-value determinator is configured to obtain one or more quantitative feature values describing one or more features or characteristics of the input audio signal and to provide the gain-values as a function of the one or more quantitative feature values, such that the gain-values are quantitatively dependent on the quantitative feature values, to provide fine-tuned extraction of ambience components from the input audio signal; and the gain-value determinator is configured to provide the gain-values such that the ambience components are emphasized over non-ambience components in the weighted sub-band signal; the gain-value determinator is configured to obtain a plurality of different quantitative feature values describing a plurality of different features or characteristics of the input audio signal and to combine the different quantitative feature values to obtain the sequence of gain-values, such that the gain-values are quantitatively dependent on the quantitative feature values; the gain-value determinator is configured to weight the different quantitative feature values differently according to weighting coefficients; and the gain-value determinator is configured to combine at least a tonality feature value describing a tonality of the input audio signal and an energy feature value describing an energy within a sub-band of the input audio signal, to obtain the gain-values.