Patent ID: 8364471

Claim:
A method for processing an audio signal, the method comprising: extracting, by an audio processing apparatus, spectral data and noise filling flag information indicating whether noise filling is used for a plurality of frames, the spectral data being inverse-quantized; extracting coding scheme information indicating whether a current frame included in the plurality of frames is coded in either a frequency domain or a time domain; when the noise filling flag information indicates that the noise filling is used for the plurality of frames and the coding scheme information indicates that the current frame is coded in the frequency domain, extracting noise level information for the current frame, and noise offset information for modifying a scale factor for the current frame, wherein the noise offset information is provided for a spectral band having a loss area corresponding to spectral data of zero; and performing the noise-filling for the current frame based on a noise level value and the noise offset information, the noise level value corresponding to the noise level information which comprises: determining the loss area of the current frame based on the spectral data of the current frame; generating a compensated spectral data of the current frame by filling the loss area with a random signal using the noise level value corresponding to the noise level information; and generating a compensated scale factor by modifying the scale factor of the current frame based on the noise offset information, wherein the compensated scale factor is applied to the spectral band corresponding to at least one spectral data.