Koninklijke Philips Corporation N.v.

Leonardus Cornelis Antonius Van Stuivenberg

Cornelis Pieter Janse

Patrick Kechichian

Cornelis Pieternella Janse

An audio signal processing apparatus comprises a receiver () receiving an audio signal sampled at a first sampling frequency, the audio signal having a maximum frequency below half the first sampling frequency by a first frequency margin. A filter bank () generates subband signals for the digital audio signal using overlapping sub-filters. A first frequency shifter () applies a frequency shift to at least one subband of the set of subbands and a decimator () decimates the subband signals by a decimation factor resulting in a decimated sampling frequency being at least twice a bandwidth of each of the overlapping sub-filters. The frequency shift for a subband is arranged to shift the subband to a frequency interval being a multiple of a frequency interval from zero to half the decimated sample frequency. The subband may be individually processed and the processed subbands may subsequently be combined to generate a full band output signal.

Audio signal processing

A noise suppressor comprises a first () and a second transformer () for generating a first and second frequency domain signal from a frequency transform of a first and second microphone signal. A gain unit () determines time frequency tile gains in response to a difference measure for magnitude time frequency tile values of the first frequency domain signal and magnitude time frequency tile values of the second frequency domain signal. A scaler () generates a third frequency domain signal by scaling time frequency tile values of the first frequency domain signal by the time frequency tile gains; and the resulting signal is converted to the time domain by a third transformer (). A designator () designates time frequency tiles of the first frequency domain signal as speech tiles or noise tiles; and the gain unit () determines the gains in response to the designation of the time frequency tiles as speech tiles or noise tiles.

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Helmond, Netherlands

Leonardus Cornelis Antonius Van Stuivenberg