Patent ID: 7493255

Claim:
Method comprising: calculating linear predictive coefficients from samples of audio signals, for providing a calculated signal indicative of calculated linear predictive coefficients; extracting, in response to said calculated signal, line spectral frequency vectors from said calculated linear predictive coefficients with an extraction rate, for providing a vector signal indicative of extracted linear spectral frequency vectors comprising values of different linear spectral frequency parameters; forming, in response to said vector signal, a track signal indicative of linear spectral frequency tracks for said linear spectral frequency parameters, which linear spectral frequency tracks represent values of respective linear spectral frequency parameters over time; low pass filtering, in response to said track signal, said linear spectral frequency tracks with a predetermined cut-off frequency for providing a low pass filtered signal, wherein less linear spectral frequency tracks than can be formed from said linear spectral frequency parameters are low pass filtered with a predetermined cut-off frequency; and reconstructing, in response to said low pass filtered signal, a decimated number of linear spectral frequency vectors from said low pass filtered linear spectral frequency tracks, said decimated number corresponding to a selected vector output rate, which is lower than said extraction rate.