Generating a wideband extension of an audio signal of extended bandwidth

Method of generating an extension of the high band of an audio signal from an envelope and an excitation, wherein the method includes the step (S1) simultaneous control of the shape of the envelope and the noise level excitation with a parameter common control f, where said envelope shape controlled (S1A) by using a formant H postfilter (z) of the form: wherein is a predictor of linear filter representing the envelope and γ1, γ2 are functions of the control parameter f.