Abstract: A method of cancelling acoustic echo in a first signal comprising an echo signal of a second signal, comprising: inserting, in an inaudible manner, into the second signal a pseudo-random sequence whose circular autocorrelation comprises a unit impulse and a continuous component; characterizing, in the first signal, by means of the inserted sequence, an acoustic channel followed by the echo signal; estimating the echo signal in the first signal by means of the characterization of the acoustic channel; and cancelling the echo signal by means of the obtained estimation.

Abstract: A technique for correcting the voice spectral deformations introduced by a communication network. Prior to the operation of equalization of the voice signal of a speaker, the constitution of classes of speakers is communicated, with one voice reference per class. Then, for a given speaker, the classification of this speaker is communicated, that is to say his allocation to a class from predefined classification criteria in order to make a voice reference which is closest to his own correspond to him. Then, for that given speaker, communicating the equalization of the digitized signal of the voice of the speaker carried out with, as a reference spectrum, the voice reference of the class to which the speaker has been allocated. This technique applies to the correction of the timbre of the voice in switched telephone networks, in ISDN networks and in mobile networks.

Abstract: A technique for correcting the voice spectral deformations introduced by a communication network. Prior to the operation of equalisation of the voice signal of a speaker, the constitution of classes of speakers is communicated, with one voice reference per class. Then, for a given speaker, the classification of this speaker is communicated, that is to say his allocation to a class from predefined classification criteria in order to make a voice reference which is closest to his own correspond to him. Then, for that given speaker, communicating the equalisation of the digitised signal of the voice of the speaker carried out with, as a reference spectrum, the voice reference of the class to which the speaker has been allocated. This technique applies to the correction of the timbre of the voice in switched telephone networks, in ISDN networks and in mobile networks.