The auditory quality of wideband audio is generally degraded due to the lack of the high-frequency in network transmission

so this paper presents a kind of audio bandwidth extension method from wideband to super wideband based on local least square support vector machine.In the light of the nonlinearity of audio spectrum

the high-frequency fine spectrum of audio signals is predicted by using phase space reconstruction and local least square support vector machine.Combining with the estimation of high-frequency sub-band energy based on Gaussian mixture model

the proposed method can effectively recover the high-frequency components in the frequency range 7kHz~14kHz through the envelope adjustment of high-frequency spectrum at last.Subjective and objective testing results indicate that the proposed method improves the auditory quality of wideband audio and outperforms the reference methods of audio bandwidth extension.