According to an aspect of the present invention, a method for reconstructing an audio signal having a baseband portion and a highband portion is disclosed. The method includes obtaining a decoded baseband audio signal by decoding an encoded audio signal and obtaining a plurality of subband signals by filtering the decoded baseband audio signal. The method further includes generating a high-frequency reconstructed signal by copying a number of consecutive subband signals of the plurality of subband signals and obtaining an envelope adjusted high-frequency signal. The method further includes generating a noise component based on a noise parameter. Finally, the method includes adjusting a phase of the high-frequency reconstructed signal and obtaining a time-domain reconstructed audio signal by combining the decoded baseband audio signal and the combined high-frequency signal to obtain a time-domain reconstructed audio signal.

Encoding and decoding systems are described for the provision of high quality digital representations of audio signals with particular attention to the correct perceptual rendering of fast transients at modest sample rates. This is achieved by optimising downsampling and upsampling filters to minimise the length of the impulse response while adequately attenuating alias products that have been found perceptually harmful.

Encoding and decoding systems are described for the provision of high quality digital representations of audio signals with particular attention to the correct perceptual rendering of fast transients at modest sample rates. This is achieved by optimising downsampling and upsampling filters to minimise the length of the impulse response while adequately attenuating alias products that have been found perceptually harmful.

What is described is an apparatus for post-processing an audio signal, having: a time-spectrum-converter for converting the audio signal into a spectral representation having a sequence of spectral frames; a prediction analyzer for calculating prediction filter data for a prediction over frequency within a spectral frame; a shaping filter controlled by the prediction filter data for shaping the spectral frame to enhance a transient portion within the spectral frame; and a spectrum-time-converter for converting a sequence of spectral frames having a shaped spectral frame into a time domain.

What is described is an apparatus for post-processing an audio signal, having: a time-spectrum-converter for converting the audio signal into a spectral representation having a sequence of spectral frames; a prediction analyzer for calculating prediction filter data for a prediction over frequency within a spectral frame; a shaping filter controlled by the prediction filter data for shaping the spectral frame to enhance a transient portion within the spectral frame; and a spectrum-time-converter for converting a sequence of spectral frames having a shaped spectral frame into a time domain.

A method and an apparatus for acquiring semantic information, an electronic device and a storage medium are provided. The method includes: collecting an echo signal of vibrations of a throat; performing a Fourier transform on a waveform of each period of the echo signal to obtain a spectrogram of each period, wherein the spectrograms of M periods form a spectrogram set, the spectrogram set includes M spectrograms, and the spectrograms are arranged in sequence from first to last according to a return time sequence of the corresponding echo signal; extracting a characteristic waveform of the vibrations of the throat from the spectrogram set; segmenting the characteristic waveform to obtain characteristic segments containing the semantic information; and inputting the characteristic segments into a semantic acquisition model to acquire the semantic information.

A method and an apparatus for acquiring semantic information, an electronic device and a storage medium are provided. The method includes: collecting an echo signal of vibrations of a throat; performing a Fourier transform on a waveform of each period of the echo signal to obtain a spectrogram of each period, wherein the spectrograms of M periods form a spectrogram set, the spectrogram set includes M spectrograms, and the spectrograms are arranged in sequence from first to last according to a return time sequence of the corresponding echo signal; extracting a characteristic waveform of the vibrations of the throat from the spectrogram set; segmenting the characteristic waveform to obtain characteristic segments containing the semantic information; and inputting the characteristic segments into a semantic acquisition model to acquire the semantic information.

A method, system, and computer program to encode and decode a channel coherence parameter applied on a frequency band basis, where the coherence parameters of each frequency band form a coherence vector. The coherence vector is encoded and decoded using a predictive scheme followed by a variable bit rate entropy coding.

A method for generation of comfort noise for at least two audio channels. The method comprises determining a spatial coherence between audio signals on the respective audio channels, wherein at least one spatial coherence value per frame and frequency band is determined to form a vector of spatial coherence values. A vector of predicted spatial coherence values is formed by a weighted combination of a first coherence prediction and a second coherence prediction that are combined using a weight factor α. The method comprises signaling information about the weight factor α to the receiving node, for enabling the generation of the comfort noise for the at least two audio channels at the receiving node.

An audio signal encoding method and apparatus, and an audio signal decoding method and apparatus are provided. The audio signal encoding method includes: obtaining a frequency-domain coefficient of a current frame and a frequency-domain coefficient of a reference signal of the current frame; performing filtering processing on the frequency-domain coefficient of the current frame to obtain a filtering parameter; determining a target frequency-domain coefficient of the current frame based on the filtering parameter; performing filtering processing on the frequency-domain coefficient of the reference signal and a reference frequency-domain coefficient based on the filtering parameter to obtain a target frequency-domain coefficient of the reference signal; and encoding the target frequency-domain coefficient of the current frame based on the target frequency-domain coefficient of the current frame, the target frequency-domain coefficient of the reference signal, a reference target frequency-domain coefficient. The method can improve audio signal encoding/decoding efficiency.