PROCEDE ET SYSTEME DE TRAITEMENT DES SILENCES DANS UN SIGNAL DE PAROLE

L'INVENTION CONCERNE LE TRAITEMENT DE LA PAROLE.UN SYSTEME DE TRAITEMENT DE LA PAROLE CONVERTIT UN CONFIGURATION DE PAROLE EN UNE SEQUENCE DE CODES NUMERIQUES ADAPTATIFS AU MOYEN D'UN CODEUR 110. UN DETECTEUR DE SILENCE 115 GENERE UN CODE NUMERIQUE REPRESENTATIF DE CHAQUE INTERVALLE DE SILENCE. UN CIRCUIT DE TRAITEMENT DE CODE 125 COMBINE LES CODES NUMERIQUES ADAPTATIFS ET LES CODES D'INTERVALLES DE SILENCE POUR FORMER UN SIGNAL CODE DE FACON NUMERIQUE QUI EST REPRESENTATIF DE LA CONFIGURATION DE PAROLE D'ENTREE ET DANS LEQUEL LES INTERVALLES DE SILENCE SONT REPRESENTES PAR UN CODE PARTICULIER SUIVI D'UN NOMBRE QUI INDIQUE LA DUREE DE CHAQUE INTERVALLE DE SILENCE.APPLICATION A LA COMPRESSION DE L'INFORMATION VOCALE. In an ADPCM system, improved detection of silence intervals in a speech signal is attained by detecting the level of the logarithm step-size signal (dn), which is representative of the energy of the speech samples. A speech pattern is converted into a sequence of adaptive digital codes. Intervals of silence in the pattern are detected and a digital code representative of each silence interval is generated. The adaptive digital codes and the silence interval codes are combined to form a digitally coded signal representative of the pattern. The conversion of the pattern to adaptive digital codes includes forming a signal corresponding to the adaptation step-size for each digital code. The silence interval detection includes producing first and second threshold signals. A silence interval signal is initiated when the adaptation step-size corresponding signal diminishes below the first threshold and the silence interval is terminated when the adaptation step-size corresponding signal increases above the second threshold after the silence interval initiation.