Abstract: A filter bank with a sufficiently high resolution for amplification and noise reduction and with the lowest possible computational complexity is provided for a hearing device and, in particular, for a hearing aid. Two-stage frequency transformation with little latency is therefore proposed for hearing aids. Some of the processing, for example the amplification, is carried out after high stopband attenuation in the first stage. An increased frequency resolution is achieved in a second stage before the back-transformation in the first stage, which is favorable for noise reduction, for example.

Abstract: A smoothing method for suppressing fluctuating artifacts in the reduction of interference noise includes the following steps: providing short-term spectra for a sequence of signal frames, transforming each short-term spectrum by way of a forward transformation which describes the short-term spectrum using transformation coefficients that represent the short-term spectrum subdivided into its coarse and fine structures; smoothing the transformation coefficients with the respective same coefficient indices by combining at least two successive transformed short-term spectra; and transforming the smoothed transformation coefficients into smoothed short-term spectra by way of a backward transformation.

Abstract: A method for modification of a cepstro-temporally smoothed gain function of a gain function resulting in a bias compensated spectral gain function is provided. The cepstro-temporal smoothing increases the quality of an enhanced output signal, as it affects only spectral outliers caused by estimation errors, while the speech characteristics are well preserved. However, due to the cepstral transform, the temporal smoothing is done in the logarithmic domain rather than the linear domain, and hence results in a certain bias. Thus, the method for a general bias compensation for a cepstro-temporal smoothing of spectral filter gain functions that is only dependent on the lower limit of the spectral filter-gain function.

Abstract: A method for determining unbiased signal amplitude estimates () after cepstral variance modification of a discrete time domain signal (s(t)), wherein the cepstrally-modified spectral amplitudes () of the discrete time domain signal (s(t)) are ?-distributed with 2{tilde over (?)} degrees of freedom. A bias reduction factor (r) is determined using the equation r 2 = ? ? ~ ? ? ? ? ( ? ~ ) - ? ? ( ? ) , where 2? are the degrees of freedom of the ?-distributed spectral amplitudes of the discrete time domain signal (s(t)) and ? ? ( x ) = - 0.5772 - ? n = 0 ? ? ( 1 x + n - 1 1 + n ) ; then the unbiased signal amplitude estimates () are determined by multiplying the cepstrally-modified spectral amplitudes () with the bias reduction factor (r) according to the equation =r.

Abstract: A filter bank with a sufficiently high resolution for amplification and noise reduction and with the lowest possible computational complexity is provided for a hearing device and, in particular, for a hearing aid. Two-stage frequency transformation with little latency is therefore proposed for hearing aids. Some of the processing, for example the amplification, is carried out after high stopband attenuation in the first stage. An increased frequency resolution is achieved in a second stage before the back-transformation in the first stage, which is favorable for noise reduction, for example.

Abstract: A smoothing method for suppressing fluctuating artifacts in the reduction of interference noise includes the following steps: providing short-term spectra for a sequence of signal frames, transforming each short-term spectrum by way of a forward transformation which describes the short-term spectrum using transformation coefficients that represent the short-term spectrum subdivided into its coarse and fine structures; smoothing the transformation coefficients with the respective same coefficient indices by combining at least two successive transformed short-term spectra; and transforming the smoothed transformation coefficients into smoothed short-term spectra by way of a backward transformation.

Abstract: A method for determining unbiased signal amplitude estimates () after cepstral variance modification of a discrete time domain signal (s(t)), wherein the cepstrally-modified spectral amplitudes () of the discrete time domain signal (s(t)) are X-distributed with 2{tilde over (?)} degrees of freedom. A bias reduction factor (r) is determined using the equation r 2 = ? ? ~ ? ? ? ? ( ? ~ ) - ? ? ( ? ) , where 2? are the degrees of freedom of the X-distributed spectral amplitudes of the discrete time domain signal (s(t)) and ? ? ( x ) = - 0.5772 - ? n = 0 ? ? ( 1 x + n - 1 1 + n ) ; then the unbiased signal amplitude estimates () are determined by multiplying the cepstrally-modified spectral amplitudes () with the bias reduction factor (r) according to the equation =.

Abstract: A method for modification of a cepstro-temporally smoothed gain function of a gain function resulting in a bias compensated spectral gain function is provided. The cepstro-temporal smoothing increases the quality of an enhanced output signal, as it affects only spectral outliers caused by estimation errors, while the speech characteristics are well preserved. However, due to the cepstral transform, the temporal smoothing is done in the logarithmic domain rather than the linear domain, and hence results in a certain bias. Thus, the method for a general bias compensation for a cepstro-temporal smoothing of spectral filter gain functions that is only dependent on the lower limit of the spectral filter-gain function.

Abstract: The invention specifies a method for noise reduction of an input signal of a hearing device. The cepstrum coefficients of the input signal, of the changed input signal and/or of at least one parameter obtained from the input signal are modified. The modified cepstral coefficients are used for formation of an output signal from the input signal. The output signal has reduced noise in relation to the input signal. With instationary noises in particular, an estimation is improved and an improved auditive quality is achieved for the hearing device.