FIELD: physics, acoustics.
SUBSTANCE: invention relates to HFR (High Frequency Reconstruction/Regeneration) of audio signals and is intended for performing HFR of audio signals having large variations in energy level across the low frequency range which is used to reconstruct the high frequencies of the audio signal. The system configured to generate a plurality of high frequency subband signals covering a high frequency interval from a plurality of low frequency subband signals. The system comprises means of receiving a plurality of low frequency subband signals; means of receiving a set of target energies, each target energy covering a different target interval within the high frequency interval and being indicative of the required energy of one or more high frequency subband signals lying within the target interval; means of generating a plurality of high frequency subband signals from the plurality of low frequency subband signals and from a plurality of spectral gain coefficients associated with the plurality of low frequency subband signals, respectively; and means of adjusting the energy of the plurality of high frequency subband signals using the set of target energies.
EFFECT: preventing undesirable noise caused by discontinuities of the spectral envelope of the high frequency audio signal.
20 cl, 14 dwg
