DISPOSTIVO E METODO PER IL RICONOSCIMENTO, ALL'INTERNO DI UNA APPARECCHIATURA TELEFONICA D'UTENTE, DI SEGNALI INVIATI DA UNA CENTRALE TELEFONICA

A device and a method for recognising, inside a subscriber's telephone set TE, having a microphone MIC, signals sent by a telephone exchange SW connected to the telephone set by means of a connection line ZL. It provides means SUB for subtracting, from the signal picked off of the connection line ZL, the signal emitted by the microphone capsule MIC of the set, after processing by a balancing circuit BAL having a transfer function similar to the transfer function of the connection line ZL. It also comprises means LO C, LTG for automatic adaptation of the parameters of the balancing circuit BAL to the characteristics of said line ZL.